Why does the boiler not turn on hot water. Why does hot water flow poorly or does not flow from the water heater

One of the problems that can happen when using a double-circuit boiler. The boiler does not heat hot water. The main and most common reason why the boiler does not heat water well is the heat exchanger is clogged.

In this article I will describe how I treat this problem. Thus, you can also get out of the situation if you have a double-circuit boiler with a plate heat exchanger.

I have a well at home and the water is very hard, so there are always problems with hot water, so I use citric acid to fix the situation.

The task is this. How to deliver this acid to the inside of the heat exchanger with the least effort. I found such a way. I have a magnetic converter at the entrance to the boiler, which should remove the hardness of the water, but it does not remove it, in my opinion this is a fiction. But for me it is good that it is installed directly at the entrance to the boiler. You can see it in the photo below.

It has an American nut on it, unscrewing which you can easily pour citric acid into the inside of the pipe.

But for this you need to turn off the water. Next to the boiler I have a collector. He is in the photo below.

Now all the ducts on it are open and with one easy movement I shut off the water supply to the boiler.

All water is blocked, now you can unscrew the American on the magnetic filter. And do not forget to come up with something, from the flowing water from the boiler, there is not much of it, but it is there. I wound up the rag.

Then I pour citric acid into the inside of the pipe.

I twist the American back and open the tap for supplying tap water to the boiler.

Now it is important to understand when the acid enters the heat exchanger. Since my water tap is located a meter from the boiler, I determine whether the acid has reached the heat exchanger to taste. I just open the faucet in short jerks and taste how “sour” went, which means the entire system from the magnetic filter to the faucet is filled with citric acid.

Next, you need to turn off the tap so that your family does not drain all the acid ahead of time.

I refuel the system at night and until the morning I have it acidified. In the morning I open the water supply valve to the boiler and drain all the acid. The water will sizzle, don't be alarmed.

A question may arise, but will the acid heat exchanger not eat through? I poked around on the forum of chemists and came to the conclusion that organic acid (citric refers to it) is harmless to copper.

I use this method as needed. If you don’t like how the boiler heats water or the pressure of hot water has become weak, I take and process the heat exchanger with citric acid.

If you have polypropylene connections to the boiler, and there is no place to fill the acid, then think of something similar, it will not take much time.

Good evening everyone! After 4 months of operation of the Baksi double-circuit gas boiler, he stopped heating hot water. Why? What is the reason? I assume that the boiler is running on untreated water and, perhaps, "overgrown" with scale or rust. What do you advise the Lord?

NURLAN_DRAGON 2015.06.21 06:21 0

User responses:
None. I don’t communicate closely with them))))) Ah, I remembered - when Dolph Lungren, Van Damme flashes on TV, ...
If other problems in connection with the move do not bother you, go quietly!...
Congratulations, Irina! Nice photo. How I love mimosa! I didn’t have to choose, my hand reached out to

The most common cause of boiler breakdowns is scale. Most likely, your boiler heat exchanger is clogged with scale and does not heat up. Solution - install special. filters. For example, magnetic or electromagnetic. They are placed in front of boilers and work for many years without requiring maintenance. See manufacturers Kema (Moscow) or Aquashield (Ufa). Good luck!

Yes, most likely your double-circuit boiler is covered with scale. That's why he stopped heating hot water! Why? Hard water! What to do? Install filter. For example, ion exchange or electromagnetic.

OBAPATEH 2015.06.21 12:26 0

User responses:
Chakapuli, chashushuli.... and many other dishes of Georgian cuisine... also fried potatoes with forest mushrooms....
I'm currently studying biology...
I can't even imagine such a thing. I alone would be bored, to all sorts of dubious companies to beat

Vaillant and Baksi boilers are particularly reliable and safe. Breakdowns of such complex equipment must be eliminated by the master. But, minor malfunctions can be removed on your own if you have a basic level of knowledge about the design of heating and heating gas double-circuit boilers Baxi, Aristan or Nayen. On the display of the Baksi double-circuit gas boiler, most of the faults are indicated. Having a decoding of errors, you can figure out what is the reason for the boiler's failure to heat water. Where to start the search if the heating of water in a double-circuit gas boiler Baksi or Vaillant does not work, and the indicator does not show an error or can it be interpreted differently? The gas boiler does not heat hot water. Why? Cause? Double-circuit boiler Baksi (baxi). If the Vaillant, Baksi, Aristan or Navien double-circuit gas boiler does not heat hot water, the secondary heat exchanger should be checked. It also tends to get dirty quickly. But, fortunately, it is easy to remove, clean and install back. What is the reason? Why is this happening?

When problems arise with the preparation of hot water in a double-circuit boiler, it is necessary first of all to determine according to which scheme the boiler operates in the DHW mode. There are two options: bithermic heat exchanger and secondary heat exchanger.

In the first case, the heating circuit and the hot water circuit are combined in one heat exchanger - the primary one. When water preparation is required, the heating circulation pump stops and the entire boiler output is given to the passing tap water.

In another case, the boiler is equipped with an additional (second) plate heat exchanger and a switch (three-way valve). When it becomes necessary to prepare water, the heat carrier from the heating circuit is directed to the second heat exchanger, through which heat is transferred to the flowing tap water. At the same time, the pump continues to work - to drive to pump the coolant in a small circle.

Therefore, for different schemes, problems with hot water should be diagnosed differently.

The most common problems:

Baksi boiler does not heat hot water well

baxi boiler does not heat water (hot water does not turn on)

If the boiler does not turn on as needed

You open the mixer valve, but the boiler does not react and does not try to ignite the burner, and no errors occur. Regardless of the scheme of operation of the DHW circuit of the boiler, a sensor is installed on the outlet pipeline, which determines that the water has begun to be parsed. It is also called a DHW flow sensor. There are different types of sensors: some simply detect the presence of water movement in the pipeline, others can quantitatively measure the flow. The latter are used to provide greater comfort due to precise control of the burner power depending on the flow rate.

In both cases, at the beginning of the water flow from this sensor, a signal must be sent to the control board. If for some reason this does not happen, the boiler will be idle.

The sensor type is easiest to determine by the number of contacts. Two means it is a closing microswitch. Three - a sensor with a flow meter.

Sensor Diagnostics

If the flow sensor is a microswitch, then for diagnostics it is enough to check the contact closure with a tester. To do this, disconnect the contacts from the sensor, connect the tester in the “ringing” mode, turn on the water tap. If the circuit does not occur, then the sensor is faulty and requires inspection and, if necessary, replacement. It happens that the accumulated dirt interferes with the circuit and it is enough to clean it. Poor quality of tap water and lack of pre-filters is the most common problem. Reed sensors contain a magnet, so they attract rust microparticles and quickly fail.

Sensors with a flow meter register the amount of water flow, which can usually be displayed on the boiler display. For BAXI boilers you need:

hold the “i” button to access the information menu for 5 seconds

use the DHW temperature adjustment buttons to scroll to parameter A08 (actual water flow through the sensor, liters per minute * 10)

Now it remains to compare the actual water flow from the tap with the sensor flow. If the actual flow does not match the value of the sensor, then most likely it needs to be replaced.

Since the mechanical part of the flow sensor is a turbine, in case of contamination, it can wedge and the signal from the sensor disappears. No signal from the flow sensor - the boiler stops heating water.

The three-way valve is installed in boilers with two heat exchangers. When a signal is received from the flow sensor, the electronics give a signal to the valve and the heated water from the first heat exchanger is sent to the second heat exchanger, where heat is transferred to the passing tap water. If, for example, actual switching does not take place (valve defective), then the heating medium will continue to circulate in the heating circuit and there will be no heat transfer to the hot water circuit.

If, for example, a valve closes the heating circuit only partially due to a malfunction, then there will be problems with insufficient heating of hot water, since part of the heat will go to the heating system.

Burner modulation errors

To heat running water, in most cases, a boiler power close to maximum is required. In modern boilers, the burner power is regulated over a wide range. Adjustment occurs by changing the amount of gas supply by the gas valve. The amount of adjustment is determined by the control board, depending on the logic of operation and settings. The process can be observed visually by the height of the flames on the burner.

If the boiler settings are set to 100% boiler power in the DHW mode, but visually the flames on the burner are weak, or obvious interruptions are visible, then you should check:

gas valve setting (static and dynamic gas pressure)

control board

Such checks may only be carried out by a qualified technician.

Temperature sensor malfunction

The boiler determines the actual temperature of hot water according to the readings of the temperature sensor. Therefore, if for some reason incorrect readings are received from it, the boiler may not work correctly in the hot water preparation mode. The temperature sensor is a thermistor with resistance versus temperature. Checking such a sensor is to measure its resistance at a known temperature. Baxi boilers are equipped with NTC sensors with an inverse dependence of resistance on temperature. At room temperature, the sensor resistance should be approximately 10 kOhm, at a temperature of 45 degrees 4.3 kOhm.

Clogged heat exchanger (reduced capacity)

Often scale or dirt build-up on the inside walls of the heat exchanger is the cause of problems with hot water. If tap water does not undergo preliminary filtration (coarse cleaning) and the temperature of hot water is too high, the heat exchanger walls become overgrown with scale and dirt over time, their thermal conductivity and flow area decrease. Each time the user increases the DHW temperature on the boiler more and more to get the desired result on the mixer. With an increase in temperature, scale forms even faster and, as a result, the DHW temperature of the boiler is at its maximum, and the water is not heated enough. This process has a particularly negative effect on a boiler with a bithermic heat exchanger. Plate heat exchangers lend themselves well to flushing.

Control board errors

The control board should be considered as the cause of hot water problems when all other checks have failed. The cause may be a malfunction in the flame modulation circuit. The boiler control unit constantly adjusts the burner power depending on the conditions, and if there is a malfunction on the board, the boiler may spontaneously reboot or turn off when reaching the maximum power, which in most cases is required in the hot water preparation mode.

As board errors, it is still possible to incorrectly configure it. But this only applies to those cases when problems appeared after its replacement. BAXI boards are universal and require customization for a specific boiler.

How to eliminate the clocking of a gas boiler in hot water mode

For heating and hot water supply of apartments and small private houses with one bathroom, double-circuit gas boilers are usually used. The owners of such boilers are often faced with the fact that either cold or hot water flows from the tap. As people say, the boiler is clocking, the DHW mode of the boiler periodically turns off and then turns on again.

The principles of adjustment described in this article, setting up the hot water supply system suitable for double-circuit gas boilers of many brands and manufacturers, as well as gas water heaters.

Why is the boiler either cold or hot water?

A double-circuit gas boiler in hot water supply (DHW) mode operates in the power range from minimum to maximum. For example, in the instruction manual for the Protherm Gepard 23 MTV boiler, it is indicated that with factory settings the maximum power is 23.3 kW., the boiler provides water heating for temperature difference dT=30 about C, at the maximum consumption of hot water 11.1 l/min.

Minimum boiler power in DHW mode 8.5 kW. It is not difficult to calculate that this minimum power is enough to heat water by the same temperature difference, for example dT=45-15=30 about C, with hot water consumption 4 l/min And for heating water flow 1.5 l/min, at which the boiler burner is turned on, it is necessary to operate the boiler with a power less than the minimum - only 3.15 kW.

The design of modern mixers is done taking into account the need to save water. In addition, boilers and columns have hot water flow limiters. For example, in a house with a boiler connected to the central water supply, the following results of measuring the maximum hot water flow were obtained: through the horn of the bath faucet 6 l/min., in washbasin 4 l/min., in the kitchen sink 5 l/min. It is convenient to measure the water flow in the taps if you call line d.36 of the service menu of the Protherm Gepard (Panther) boiler, or measure the time it takes to fill a 3-liter jar with water (there is a stopwatch in the smartphone).

Usually, in order to save money, users do not open the water taps for full flow. In addition, to obtain a comfortable temperature, hot water is always mixed with cold.

The burner of the boiler in the DHW mode turns on at a water flow of 1.5 l/min Turns off at 1.1 l/min This hysteresis is a protection against periodical switching on/off of the burner due to fluctuations in the flow rate.

Considering all these circumstances, the actual amount of water that the boiler should heat per minute will be approximately equal to - 1.5-4.5 l/min.

It is obvious that the difference between the factory settings of the minimum and maximum boiler power, designed for heating 4-11.1 liters per minute, and the power required to heat the actual flow in the tap, will be significant. Boiler burner power within the minimum and maximum power settings (8.5 - 23.3 kW) is controlled automatically. Obviously, there is a huge difference between the boiler power settings and the power required to heat the actual water flow (3.15 - 9.4 kW), leads to the fact that the boiler automation is not able to bring the boiler output in line with the needs of the DHW system.

A large excess of the factory-installed power of the gas boiler in the DHW mode over the power required to heat hot water in the taps of the users leads to the cycling (clocking) of hot water heating. The burner of the boiler in the DHW mode periodically turns on and off. Accordingly, from the tap comes either cold or hot water.

Setting, adjusting the temperature of hot water in the DHW system

Diagram of heating tap water by a double-circuit gas boiler depending on temperature ( T about C) and consumption ( Q l/min) hot water. The thick line shows the borders of the Working area. Gray zone, pos. 1 — boiler clocking zone (switching between ON/OFF).

For normal water heating by the boiler, on the diagram, the point of intersection of the temperature and hot water flow lines (working point) must always be inside the working zone, the boundaries of which are shown on the diagram with a thick line.

If the hot water consumption mode is selected so that the operating point will be in the gray zone, pos. 1 in the diagram, the boiler will cycle. In this zone, with a small flow of water, the boiler power is excessive, the boiler is switched off from overheating, and then switched on again.

It can be seen from the diagram that the boiler can normally heat water only when the hot water flow from the tap is in a limited range, 4-9 l/min. With a low flow rate, the boiler power is excessive and it cycles. And with a large one, the boiler power is not enough to heat the water to the required temperature.

As mentioned above, there is no need to prepare large streams of hot water in the house. It is much more important to ensure comfortable use of hot water at a low consumption. To this end, the working area on the diagram must be moved to the left. It can be done if you reduce the power of the boiler burner by reducing the gas supply by adjusting the gas valve.

How not to deal with clocking

Some "experts" advise setting the hot water temperature lower, less than 45 o C, in order not to dilute the water in the mixer when parsing water, and open the taps to full passage. Thus, it is proposed to get rid of clocking, increasing the flow of heated water to the maximum. In many cases, this really helps, since the water flow and temperature fall into the working area on the diagram.

In DHW systems with a double-circuit boiler or with a gas water heater I don't recommend doing that, and that's why. With this method, you have to spend water, and hence gas, much more than necessary. In addition, it is always necessary to keep a large flow of water from the tap, it is impossible to regulate the temperature of the water with a mixer - all this creates discomfort in using hot water.

In addition, the display of a double-circuit boiler with a secondary DHW plate heat exchanger does not show the temperature of the hot water at the outlet of the boiler, but the temperature of the heating water at the outlet of the heating circuit of the DHW heat exchanger (return temperature from the DHW heat exchanger).

In systems with a double-circuit boiler, in which water is heated in the secondary DHW heat exchanger, the automation controls and maintains a constant temperature of the heating water at the outlet of the primary circuit of the DHW heat exchanger (return temperature from the DHW heat exchanger), and the temperature of the hot water at the outlet of the secondary circuit of the DHW heat exchanger is not controlled.

The temperature of the hot water at the outlet of the boiler will be as it turns out, depending on the degree of opening of the tap, on the temperature and pressure of the water in the water supply, on the thickness of the scale layer. That is, each time the tap is opened, the temperature of the hot water will be different.

Therefore, the required hot water temperature at the outlet of the boiler cannot be pre-set on the display. If you set the heating water temperature on the display, for example 50 about C, then the temperature of hot water from the tap will always be less, and less each time in different ways.

In a hot water system with a double-circuit boiler, it is more convenient to regulate the water temperature directly at the tap at the time of disassembly, mixing it with cold water in a mixer. To make this possible, it is necessary to have some margin for the temperature of the water at the outlet of the boiler.

For comfortable use of hot water from a double-circuit boiler or column, I recommend set the temperature on the display in DHW mode to 52 about S.

Temperature value 52 about C chosen for the following reasons:

• At a temperature of 54 about C and higher from tap water, an intensive release of hardness salts begins, which accumulate in the heat exchanger in the form of scale. Heating the water to a lower temperature protects the heat exchanger from scale deposits.
• Temperature 52 about C remains high enough and allows you to adjust the comfortable temperature of the water in the faucet by mixing hot water with a small amount of cold water. In rare cases when a higher temperature is required (for example when filling a bath), it is more beneficial to increase the DHW temperature setting on the boiler display.

The intensity of scale deposits in hot water depends on the temperature and speed of water movement near the heating source. According to studies, in still water, when the water in the tank is heated, the stone begins to form already at a temperature of 40 °С. With a high flow rate of hot water in the flow heat exchanger, the stone begins to form at temperatures above 54 °С.

Setting the boiler burner output in DHW mode

In order for the boiler in the DHW mode to heat the water evenly, not to cycle even with a minimum water flow, it is necessary to reduce the burner power, by reducing the gas supply by adjusting the gas valve. Thus, the entire work area on the diagram will move to the left. To do this, on the gas valve, reduce the factory settings for the minimum and maximum pressure at the gas outlet from the valve, in front of the burner.

As a result of adjusting the gas valve, there will be no signs of clocking the burner in the DHW mode when the hot water flow changes over the entire range, from the maximum (6 l/min) to the minimum specified in the instructions (1.5 l/min). The temperature of hot water can be regulated by a mixer, changing the flow of water and mixing it with cold water within limited, but quite comfortable limits.

Adjustment, adjustment of the SIT gas valve

SIT gas valve.

SIT gas valve. 1 - measuring fitting of gas pressure at the outlet of the valve, in front of the burner; 2 - adjusting nut for maximum pressure (flow) of gas; 3 - adjusting screw for minimum pressure (flow) of gas; 4 — cover of the adjusting device; 5 - measuring fitting of gas pressure at the valve inlet, in the gas network.

Manufacturers of double-circuit gas boilers of many brands install a gas valve from the Italian company SIT on the boilers. The settings for the maximum and minimum power of the boiler burner are made by turning the gas pressure adjusting screws located on the valve body.

A U-shaped pressure gauge is connected to the measuring fitting (1) to control the gas pressure in front of the burner. The gas pressure value corresponding to the minimum and maximum boiler power is indicated in the factory instructions. For example, for a Protherm Gepard 23 MTV boiler with a minimum power of 8.5 kW corresponds to pressure 15 mm w.c.(millimeters of water column). For maximum power 23.3 kW gas pressure at the fitting should be 85 mm w.c.

Adjustment of gas pressure in front of the burner in DHW mode

about C.

We remove the cover from the boiler and provide access to the gas valve and the ability to observe the height of the flame in the burner. We recommend connecting a U-shaped manometer to the measuring socket (1) of the gas valve.

On the gas valve, remove the cover of the adjusting device (pos. 4 in the figure). The initial position of the adjusting devices - nuts and screws, relative to the body, mark with a colored marker, if it is necessary to restore their position.

with maximum water flow(horn in bathroom 6 l/min).

Adjust (reduce) the gas pressure in front of the burner using the nut for adjusting the maximum gas pressure (pos.2). When turning to the right, the gas supply increases, and when turning to the left, it decreases. The purpose of the adjustment is to find the limit when further rotation of the adjusting nut leads to a decrease in the height of the flame in the burner, to a decrease in the temperature of hot water from the tap and to a decrease in gas pressure at the measuring point (1). Leave the nut in a position close to the boundary found.

As a result, the maximum power of the boiler will become less, and the right border of the working area on the diagram will shift to the left, to the point with coordinates, for our example, 60 about C and 6 l/min.

Set the hot water temperature on the boiler display to 52 about C. (see above for setting the DHW temperature)

On the gas valve, disconnect the modulator power cable. The boiler will go into minimum power mode.

Turn on the DHW mode on the boiler by opening for the minimum flow hot water tap with sufficient water flow to turn on the boiler burner.

Adjust (reduce) the gas pressure in front of the burner using the minimum gas pressure adjustment screw (pos.3). When turning to the right, the gas supply increases, and when turning to the left, it decreases. Visually observe the height of the flame in the boiler burner. The purpose of the adjustment is to reduce the gas supply to the burner (flame height) so that the burner works continuously and the temperature of the hot water from the tap remains constant, the boiler does not clock.

As a result, the minimum power of the boiler will be reduced. The left border of the working area on the diagram will shift further to the left, to the point with coordinates, for our example, 52 about C and 2 l/min.

Do not attempt to reduce the minimum pressure at the outlet of the gas valve too much. A very small gas pressure on the burner can lead to a violation of the stability of combustion, to the breakdown and extinction of the flame.

Reconnect the modulator power cable and replace the modulator cover.

We control the gas pressure in the network

The gas pressure in the gas network may drop below that allowed for the operation of the boiler. It is necessary to periodically control the pressure, especially in cold weather, when the gas flow in the network is maximum.

Static pressure and dynamic pressure are measured at the boiler inlet. Static pressure is when the boiler does not consume gas. The dynamic pressure is measured at the maximum gas flow rate of the boiler.

The pressure in the gas network, at the inlet of the gas valve, is measured by attaching a tube of a U-shaped pressure gauge to the fitting pos.5. To measure the dynamic pressure, open the hot water tap to the full passage.

The normal dynamic gas pressure at the gas valve inlet should be between 1.3 - 2.5 kPa (13 - 25 mbar or 132 - 255 mm. water. Art.). If during the measurement the value of the dynamic pressure goes beyond the specified limits, then it is necessary to contact the gas service.

How to measure the gas inlet pressure and adjust the minimum and maximum gas pressure at the outlet of the SIT gas valve, see this video.

A simple manometer for measurements on a gas valve can be made from a transparent plastic tube, filled with water and bent in the shape of a U. One end of the tube is put on the valve fitting, and the other is left open. The ruler measures the difference in water levels in the branches of the tube. The measured distance will be equal to the pressure in millimeters of the water column - mm w.c..

On the gas valve fitting, you can tightly pull a tube with an inner diameter of 8 mm. For a tube of a different diameter, you will have to select an adapter.

At the end of the measurement, do not forget to carefully tighten the locking screw on the measuring nipple and check its tightness.

Adjustment, adjustment of the Honeywell gas valve

Gas valve Honeywell gas boiler. The yellow wired connector is mounted on the stepper motor.

Some modern boilers, such as Protherm Gepard and Protherm Panther, have Honeywell gas valves.

The gas pressure setting at the outlet of the Honeywell gas valve is changed using a stepper motor. The stepper motor of the gas valve is controlled from the boiler control panel through the service menu.

We will consider setting up a gas valve with a stepper motor through the service menu using the example of Protherm Gepard and Protherm Panther gas boilers.

Access to the Protherm boiler service menu

The electromechanical devices of the boiler (electrovalves, stepper and conventional electric motors, sensors) are controlled by the microprocessor of the electronic control board in accordance with the programmed program.

The settings of the boiler operation program can be changed on the control panel using two menus - a public user and hidden service menu.

Access to the service menu of the Gepard boiler

The Protherm Gepard boiler is controlled from the control panel through the public user menu. How the owner manages the boiler is written in the instruction manual.

On the control panel, you can call up another hidden menu - a service menu intended for specialists. The service menu becomes available on the display screen after entering the code.

Press and hold the mode button (1) for about 7 seconds; the display will change - a number will appear 0 . - With buttons + or - (2), enter code, number 35 . - Confirm the code entry by pressing the mode button (1). After that, the display will show the 1st menu line in the form of symbols interspersed on the screen: d. 0.

Buttons + or - d.**.

Press the "mode" button to change from menu bar number designation " d.**” to the parameter value (the display alternates between the “=” symbol and the parameter value). - Change the values ​​of the displayed parameters using the + or - buttons (3) on the boiler panel. - 3 seconds after the change, the new values ​​are automatically confirmed. To reset the display, press the "mode" button for 3 seconds. After 15 minutes of inactivity, the display returns to normal on its own.

Access to the service menu of the Panther boiler (Panther)

The control panel of the Protherm Panther boiler has some differences from the Protherm Gepard boiler. The boiler control panel has a hidden service menu, which becomes available when entering the code.

To access the service menu of the Protherm Panther boiler (Panther), you must: Press and hold the mode button (1) for about 7 seconds; the display will change. - Via buttons on the left + or - (2), enter the access code in the service menu - the number 35 in the left half of the display. - Confirm the code entry by pressing the mode button (1).

After that, the display will show the 1st line of the menu in the form of symbols d.00 with the menu line number in the left half of the display, and the numeric value of the line parameter in the right half of the display. - Via buttons on the left + or - (2), enter the number with the required menu line number: d.**.

To change the value of a parameter in the menu bar:- Change the values ​​of the displayed line parameters with buttons on the right + or - (3) on the boiler panel. - 3 seconds after the change, the new values ​​are automatically confirmed. To reset the display, press the "mode" button for 3 seconds. After 15 minutes of inactivity, the display returns to normal on its own.

The service menu commands and the procedure for setting the power of the Protherm Panther boiler (Panther) are similar to those given for the Protherm Gepard boiler.

Description of some service menu commands

Line d.36- shows on the display the hot water consumption measured by the flow sensor, l/min. when dispensing hot water (read-only).

Let's determine the consumption of hot water in our apartment (in the house). Line d.36 of the service menu shows on the display the hot water consumption measured by the flow sensor, l/min. We display the line parameter d.36 on the display, then open the DHW taps in the apartment (in the house) one by one for full flow and record the water consumption readings from the display.

Line d.52- setting the minimum power of the boiler burner by shifting the minimum position of the stepper motor of the Honeywell gas valve. The range of possible parameter values ​​is from =0 to =99. The smaller the value of the parameter, the weaker the intensity of gas combustion.

Line d.53- setting the maximum power of the boiler burner by shifting the maximum position of the gas valve stepper motor Honeywell. The range of possible parameter values ​​is from =0 to =-99 (negative values ​​with a minus sign). The smaller the value of the parameter, the weaker the intensity of gas combustion.

Line d.88- Protection against water hammer in the distribution of cold water (for boilers KTV and KOV) . The ability to change the parameter leads to the elimination of the reaction to water hammer, which occurs in some cases in cold water pipelines. For example, at the moment the automatic valve closes in the toilet flush tank (or washing machine or dishwasher), a pressure surge (water hammer) may occur in the water pipes. This may result in a false operation of the tap water flow sensor (turbine), which will lead to a short-term unwanted activation of the boiler's DHW mode. Factory setting 0 = activation of the ignition process for heating tap water at a flow rate of 1.5 l/min. Changing the parameter to value 1 = activation of the ignition process for heating tap water at a flow rate of 3.7 l/min. In this case, the duration of the flow must be at least 2 seconds.

Line d.96- Setting the boiler to the parameters set from the factory. In case the setting leads to incorrect operation or failures, it is possible to restore the factory settings of the boiler. Setting: 0 - replacement with factory settings will not be performed; 1 - will return to the factory settings Note: when you enter the setting of this parameter, the display always shows the parameter "0".

Setting, adjusting the minimum power of the boiler with a Honeywell gas valve

The boiler manufacturer Protherm Gepard (Panther) on some versions of the boilers, instead of the Honeywell gas valve, installs the SIT 845 Sigma gas valve. The setting of this valve is described above. There are no lines d.52 and d.53 in the service menu of Protherm boilers with SIT valve.

Setting the maximum gas pressure:

On the boiler display, set the maximum hot water heating temperature to 60 about C.

We remove the cover from the boiler and provide access to the gas valve and the ability to observe the height of the flame in the burner. I recommend connecting a U-shaped pressure gauge to the measuring fitting at the valve outlet.

Turn on the DHW mode on the boiler by opening the hot water tap to full flow with maximum water flow(horn in bathroom 6 l/min).

d.53, press the “mode” button and see on the display the value of the gas valve stepper motor position parameter in the maximum power mode. For example, on a new boiler, the factory setting of the maximum power parameter in the line d.53 was = -17 .

Decrease the value of the parameter in line d.53 step by step and fix the result. For example, set the line to =-30 (minus 30 is less than minus 17) and press "mode" for the changes to take effect. We look at the height of the flame in the burner and the value of the gas pressure. They haven't changed.

The purpose of the adjustment is to find the limit when a further decrease in the parameter in line d.53 leads to a decrease in the height of the flame in the burner and to a decrease in gas pressure at the measuring point. In our example, the flame height and pressure began to decrease when the parameter in line d.53 was set to less than = -70 (remember, factory setting = -17)

As a result, the right border of the working area on the diagram will shift to the left, to the point with coordinates, for our example, 60 about C and 6 l/min. The maximum power of the boiler will be reduced.

Setting the minimum gas pressure in front of the burner:

To adjust the gas valve, the boiler is switched to DHW mode. For this, we open for the minimum pass hot water tap with a flow rate sufficient to turn on the boiler burner.

In the service menu, select the line d.52, press the “mode” button and see on the display the value of the gas valve stepper motor position parameter in the minimum power mode. For example, on a new boiler, the factory setting of the minimum power parameter in the line d.52 was = 72 and the burner cycled in DHW mode.

We carry out experiments - reduce the value of the parameter in the line d.52 =60 , press "mode" to make the changes take effect, and check the result. If the clocking has not stopped, then we also reduce the parameter in the line d.52 = 50 and observe the change in the temperature of the hot water in the tap. So, step by step, we reduce the parameter in line d.52 until we achieve the absence of temperature fluctuations at a comfortable water flow.

We reduce clocking to an acceptable comfortable level. Do not attempt to reduce the minimum pressure at the outlet of the gas valve too much. A very small gas pressure on the burner can lead to a violation of the stability of combustion, to the breakdown and extinction of the flame.

For example, on a new boiler, the temperature of hot water in the tap reached 52 about C, after setting in line d.52 parameter =30 (remember, the factory setting was =72). There were no signs of burner cycling in the DHW mode when the flow rate changed over the entire range, from the maximum (6 l/min) to a minimum of 1.5 l/min. The temperature of hot water can be adjusted with a mixer, changing the flow rate of water and mixing it with cold water within limited, but quite comfortable limits.

How will the settings of the gas valve for domestic hot water affect heating

Reducing the pressure setting at the outlet of the DHW gas valve will also lead to a slight decrease in the boiler output in heating mode. But in most cases, the maximum output of a combi boiler is chosen to cover water heating requirements that exceed the required output for the heating system.

For our example, the maximum boiler power will decrease from 23.3 kW. up to 12-14 kW. This power will be enough to heat a house with a heated area of ​​up to 140 m 2.

The maximum power of a double-circuit boiler is usually more than is necessary for heating operation. Therefore, after setting the DHW mode, in most cases, it is enough to increase the maximum power setting when the boiler is operating in heating mode. How to do it

If the boiler power in heating mode is still insufficient, you will have to restore the factory settings of the gas valve. In this case, to eliminate the DHW clocking, I recommend connecting a boiler to the boiler.

About the disadvantages of reducing the boiler power settings

The service manual for the Protherm Gepard 23 MTV boiler indicates its efficiency in heating mode: 93.2% at maximum heat output (23.3 kW.) and 79.4% when operating at minimum power (8.5 kW.) Imagine how the efficiency will decrease even more if this boiler has to work with a minimum power of 4 kW. Please note that a double-circuit boiler during the year most of the time operates in heating and hot water mode with a minimum power. At least 1/4 of the consumed gas will literally fly uselessly into the pipe. But clocking, as already mentioned above, also reduces the efficiency of the boiler, leads to excessive consumption of water and gas, and makes the use of water uncomfortable.

In the comments to the article, the reader Sergey writes:“The manufacturer did not just set the minimum and maximum power of the boiler. According to you, if it were all so simple, then the manufacturer, with the help of its service representatives, would reconfigure the boilers as you are talking about it. But the manufacturer in these cases insists to deal with the pressure and not with the boiler. As I understand it, this is due to the fact that changing the minimum / maximum range on the burner is dangerous, for the boiler in the first place. If the pressure of the supplied gas to the burner is lowered, the flame will go down, in which case the burner will be damaged over time?

And this is my answer to Sergey:“My boiler has been working for the fifth year. Every summer I clean and inspect the burner. I don't see any signs of damage or overheating. I do the same for others. There is no protection against low gas pressure on the boilers. So the manufacturer believes that it is not dangerous.
Low pressure is dangerous for boilers with burners, in which the gas is pre-mixed with air and the already prepared mixture leaves the burner. Then yes, at low pressure, the flame can even slip into the inside of the burner and really damage the burner.
Most household boilers do not have a burner like this. There is a danger of extinguishing, blowing out the flame, but the boilers have protection that will turn off the boiler and give an error.
The choice is up to the owner - either live with clocking, or change settings, or buy a boiler or another boiler.
Manufacturers, sellers and specialists actually deceive buyers, with rare exceptions, they do not inform them about the cycle time of a double-circuit boiler at low water consumption. Buyers think that there will be normal hot water at the minimum flow rate specified in the instructions, and then it turns out that this is not the case. Reconfiguring greatly reduces the efficiency of the boiler. This information is not in the instructions and descriptions for users. If all this was explained to buyers, they would buy other boilers.”

We choose the power of a gas boiler for the house correctly

Most gas-fired double-circuit boilers that are commercially available are designed to operate with a minimum heat output. over 8 kW.

Some manufacturers began to "cunning". In the boiler control program, limit maximum heat output in heating mode. And indicate its value in the designation of the brand of the boiler. Boilers appeared on sale with an indication of the power in the brand of the boiler, for example - 12 kW. At the same time, in the boiler passport, the maximum power in the DHW mode remains 20 - 24 kW., and the minimum in all modes is more than 8 kW.

On sale you can also find double-circuit gas boilers with a maximum heat output of 20 - 24 kW. and minimum less than 5 kW. Such boilers are best suited to the needs of heating and hot water systems of small private houses and apartments. At maximum power, the boiler operates in DHW mode. At minimum power - in heating mode.

For the preparation of hot water and heating houses and apartments with a heated area up to 120 m 2, with one bathroom, I recommend installing double-circuit gas boilers with an extended operating power range:

• • with a maximum power of 20 - 24 kW.
  • and minimum less than 5 kW.

Filter at the heating water inlet to the DHW heat exchanger

Problems with hot water heating sometimes arise and are aggravated due to clogging of the filter installed at the heating water inlet to the DHW plate heat exchanger. The filter protects the DHW plate heat exchanger from dirt from the heating circuit.

If the filter is heavily clogged with dirt, then in DHW mode this most often manifests itself as an error: “overheating of the primary circuit at the supply (NTC2)”. The overheating protection is activated and the boiler is switched off.

For all brands of boilers, the filter is removed in different ways. But this procedure usually does not present any particular difficulties. No special tool is required. But it would be better to find instructions, a website, pictures or videos on the Internet on this topic. For the first time, you can invite a service specialist and see how he removes the filter.

Cleaning the hot water filter of double-circuit gas boilers Protherm Gepard and Panther (Panther)

1 - mounting rails, heat exchanger holders; 2 - holder screw; 3 - gasket; 4 - heating water filter at the inlet to the heat exchanger; 5 - DHW heat exchanger of a gas boiler;

To clean the DHW heat exchanger filter:

1. Close the taps on the supply and return of heating water.
2. Open the drain valve on the boiler, on the right under the pump, and drain the heating water from the boiler.
3. Close the tap at the cold water inlet and disconnect the cold water tube from the boiler. Water will drain from the boiler through the open cold water pipe. Open the hot water taps to completely empty the DHW tract from the water.
4. Remove screws (2) and holder (1) from both sides of the plate heat exchanger.
5. Remove the DHW plate heat exchanger (5). The body of the plate heat exchanger is pressed with mounting rails to the base. After the tires are removed, pull the heat exchanger up and remove it.
6. Remove spacers (3).
7. Remove the filter (4) from the hydro group.
8. Clean the filter and put everything back.

It is recommended to change the gaskets between the heat exchanger and the base (3) every time during installation. DHW heat exchanger gasket, rubber ring: 22.2x13.5x5 mm. From the inside - an annular recess. Article number: 0020014166 (10 pieces).

When reinstalling, check the correct location of the heat exchanger - the markings on its side wall should look forward. I encourage you to take a moment and descale the heat exchanger removed from the boiler. How to do this - read the following article on this topic.