DIY baxi gas boiler heat exchanger repair

Italian-made Baksi gas boilers have recently become widespread among private traders. This equipment is represented by a wide range of boilers from the most compact to industrial, starting with a power of 18 kW. Wall-mounted and floor-standing, conventional and condensing are available.

Baksi products compare favorably with competitors in high reliability, productivity, long service life and relatively low cost. The decisive advantage of Baksi boilers is that they are able to operate with voltage drops and gas pressure drops.

Baksi have little noise and are easy to use. The manufacturer guarantees uninterrupted operation of boilers for up to 5 years. In addition, the current local repair of boilers is carried out by hand. Components and spare parts are available in our markets.

The best option for apartments is a wall-mounted double-circuit boiler. Such models are produced in several series, differing in power, smoke exhaust system and type of gas burner. For apartments, it is recommended to choose an appliance with a forced draft. The calculation of the power is simple - the square of the living space is divided by 10. This gives the required boiler power in kW.

Small boilers of the Main series with a bithermal heat exchanger, to the tubes of which copper plates are spot-welded. This increases the efficiency. The design includes an expansion tank and a circulation pump. Filtration of incoming water is provided. The heat exchanger is installed on top of the firebox.

Combustion chambers of Baksi boilers are made of metal and are covered with a heat insulator from the outside.

The system works in the same way as all gas boilers. The signal from the thermostat goes to the pump, which creates a vacuum in the return. Water under low pressure (less than 0.45 bar) enters the heating system. The ignition takes place automatically.

The output power rises smoothly with increasing temperature. When it reaches the set value, the operating mode will switch from heating to modulation. When the temperature drops, the thermostat will command the inlet valve to open and the water will be heated again.

If the burner shuts down due to over-power immediately after starting, then restarting is allowed after three minutes.

Hot water is supplied as follows. Water is supplied through a three-way valve that blocks the heating line and enters the secondary circuit. There it heats up and goes to taps for personal use.

But no matter how hassle-free the Baksi is, it also breaks down sometimes.

Suppose the boiler began to work intermittently. Do not despair and immediately run to the service. You can do diagnostics and simple repair of Baksi boilers with your own hands. This is not about serious breakdowns. Frequent malfunctions in which it is recommended to try to repair Baksi boilers with your own hands:

• The burner does not turn on or periodically turns on and off.
• There is no ignition.
• Combustion chamber popping and shaking.
• The boiler is heating up too much.
• The water is not warming up enough.
• Excessive operating noise from equipment.
• Malfunction of any sensor.

The probable causes of such malfunctions are as follows:

• Moisture entering the boiler.
• Unsatisfactory quality of the coolant.
• Decrease or surges in gas pressure.
• Changes in the voltage network of 220 volts.
• Incorrect installation of the heating system.

If the flame is not powerful due to improper operation of the gas valve, a pressure adjustment in the system is required. This must be done in accordance with the requirements of the instructions. The diode bridge often fails. Then not a repair is required, but a complete replacement.

When the boiler turns off immediately after starting, then the reason for this deviation is the lowered gas pressure. The repair is reduced to reducing the pressure by adjusting from the standard 20 to 5 mbar.

If the coolant does not heat up well, check the pressure at the outlet of the gas valve. Change the position of the regulator and try to restart the boiler. That's the whole repair.

If there are deviations in the readings of the sensors, they need to be changed.

When the temperature is unsatisfactory in the DHW, check the functionality of the three-way valve. They wait until the water has completely cooled down, then close the heating taps, and then turn on the heater again to supply hot water. If heating goes on in heating, the valve is faulty. It needs to be replaced.

When strong pops are heard at the moment of ignition, the reasons for what is happening are as follows:

• Gas supply pressure too low.
• Increased distance from nozzle to igniter (due to improper transportation).

In such cases, it is necessary to adjust the clearance. It should be within 4-5 mm. Open the front panel, unscrew the electrode fastening screw, remove the electrode, bend it a little and put it in place.

When the water temperature drops sharply, the cause is looked for in clogged filters. Cleaning required, sometimes replacement. This happens as a result of mechanical damage to pipes and radiators, which are corny clogged. They are cleaned and, if necessary, changed.

It is sometimes impossible to repair Baksi boilers with your own hands without knowing the fault codes. The devices have a built-in monitoring system that diagnoses failures and displays them on the device display in alphanumeric terms.

Conventionally, such refusals are divided into two groups:

• Leading to a complete stop of the equipment.
• Leading to the transition to standby mode.

If the boiler or one of the functions has stopped working, try to restart it manually. If no serious damage has occurred, the lock will be released. This is an electronics failure. If the failure is caused by overheating of the equipment, there is no traction or the cessation of gas supply, then it will not be removed until the factor that caused it disappears.

More often codes E01 and E10 drop out.

The first is the most common. This is a sign that the flame monitoring sensor is on. It can be caused by the following reasons:

• Gas cut off.
• Incorrect phase distribution (if the model is phase-dependent).
• Failure of the flame sensor itself (it is dirty).
• Failure in the ignition system.
• Gas valve failure.
• Insufficient air supply.
• Low gas pressure.

First of all, check if the gas supply valve is on, and then connect the sensor. Next, you need to press R and hold for three seconds. The error should disappear from the display. An electronics failure has occurred. If this code appears again, you need to contact the service.

The second code pops up in the event of a malfunction of the sensors that control the circulation of water and the operation of the pump. Reasons for triggering:

• Low pressure of the heating medium.
• There is no contact between the board and the pressure switch.
• Faulty pressure switch.
• Malfunction of the pump operation sensor.
• Malfunction of the pump itself.
• Heat exchanger clogged.

In these cases, it is better to immediately contact the service center. An exception is pump failure. They change it with their own hands. You can clean the filters yourself. The rest is the prerogative of specialists.

If codes E96, E97, E98 appear, they urgently call the service center. These errors are associated with failures of the electronic board, which is not recommended to be repaired with your own hands.

The video shows the boiler repair:

To clean the primary circuit, drain the water from the heater. For these purposes, unscrew the tap on the body (usually located on the right).

Cleaning is carried out with Jelly using special liquids. The device is connected to the boiler through the nozzles, liquid is poured into it and connected to the network. Cleaning is carried out for two hours with a change in the direction of fluid flow in manual mode. After that, the liquid is drained and the boiler is collected in its original state.

The secondary circuit is also cleaned with special fluids. Only in this case, the gas tap is turned off, and the hot water tap remains open. The cleaning fluid runs in a short circle.

All my life I have been soldering copper heat exchangers near gas columns with ordinary tin-lead solder with a 100 W soldering iron. The burner is much worse, because when soldering with a soldering iron, mechanical tinning is obtained, which is much stronger than chemical. Naturally, this does not negate the use of a good flux. The main thing is to dry everything thoroughly and warm it up, so as not to make “cold soldering”, which will come off at any moment. If the leak is not heated with a soldering iron, I help with a construction hairdryer set at 300 degrees. There was not a single case of return. There, the working conditions for solder are light, maximum 100 degrees, so the use of high-temperature solders is pointless, only there is a chance to burn through the heat exchanger.

Naturally, it makes sense to solder only if the soldering point is convenient. It is theoretically impossible to solder any bithermal heat exchangers from Beretta or BAXI if the breakdown through the inner pipe (DHW)

Boiler, flow for various reasons: carelessness and negligence of the boiler owners (long-term use of the boiler without an expansion tank (downloaded)), scale build-up and soot coating of the heat exchanger, etc. all this leads to the fact that the heat exchanger begins to flow and it usually flows at the butt places (where the integral elements of the heat exchanger are connected to each other). Yes, it is inconvenient to solder, and the material of the heat exchanger is not pure copper

but anything is possible. Berets and baksi, etc. are soldered. by the way, I have never met that the heat exchanger, if it is a biterm, had a leak of internal connections. only on the forum here I read that this is possible In addition to boilers, we also deal with air conditioning, so there is welding for copper (propane - oxygen), everything is beautifully neat and without 100W soldering irons. even by capillary welding using low temperature solder and a torch, we do not solder the heat exchangers.

P.S. Regarding the soldering of 100W heat exchangers with soldering irons. sorry, but nonsense. there may be some kind of connections that are not in contact with fire and can be soldered, but a surface that is in contact with fire. soldering iron. We had a client, he soldered everything using this technology, turned on the boiler, it worked for 3 minutes and the heat exchanger collapsed before our eyes (in a figurative sense)

Baxi is a line of gas boilers from an Italian manufacturer. The best option for keeping the room at a comfortable temperature. Gas boilers of this company are safe, environmentally friendly, durable, practically silent, durable and economical, have high performance and are quite easy to operate, in addition, they have an affordable price. Even if a decrease in gas pressure is noted in the network, the boiler will not stop working. Baksi boilers run on liquefied natural gas. The modern design allows you to organically arrange the boiler in the interior of any room.

In order to choose the correct spare parts for the boiler after an identified breakdown, you need to know its series and model. The most common: Baxi Luna (Comfort, Comfort Combi, Silver Space), ECO, Nuvola (come with a stainless steel boiler), Slim, Main.