What are the most common reasons why pressure drops in a heating system with a wall-mounted boiler?
Pressure in expansion tank — the indicator for which the device is used.
Control and stable operation ensure long-term operation heating systems.
The pressure in a gas boiler can drop for various reasons.
Content
Reasons why pressure drops in a double-circuit gas boiler
Malfunctions are difficult to detect without professional equipment. Common causes include:
- Lack of power supply.
- Coolant leak.
- Malfunction of the expansion tank.
- Incorrect calculation of the system, respectively, installation of unsuitable equipment.
A decrease in pressure leads to a stop in operation. This is due to a drop in the level of: liquid in the device, which cannot flow into it, or gas, which leads to automatic shutdown. To prevent such situations, periodic maintenance is carried out, including diagnostics and repair of damaged components.
Power outage
If the boiler is fed from electricity, then it is able to work for some time without it. But a long absence will lead to a stop in operation, which will cause a drop in pressure in the system. The solution to the problem is to install backup power supply. It is expensive, but effective. Or a more capacious accumulator for the boiler is purchased.
Leak in the heating system
During the operation of the circuit, the pipeline gradually becomes unusable: scale and rust accumulate. This problem is solved cleaning pipes.
But a leak can also occur, for example, when a crack forms. Due to the loss of coolant, the pressure decreases.
The malfunction is being fixed in two ways: individual points are covered or the pipeline is replaced.
Air release from the expansion tank
If there are any problems, gas may leak from the device. This will lead to a decrease in its pressure and an increase in the same indicator of water. To fix the problem, you need to find and seal the leak, then replenish the losses. The reasons are also problems with the feed tap. In such a case, you will have to replace the entire device.
If there are no leaks - common reasons
Among other malfunctions, air locks are distinguished, which must be removed. They cause noise, vibration of the harness. The latter loosens the system, which worsens the situation by widening leaks and weakening connections. And it also accelerates the formation of corrosion, cold spots appear in the pipes.
Attention! Gas locks also form when the circuit is filled with water incorrectly, blockages, valve malfunctions.
There may be no pressure drop, but the pressure gauge shows a low reading.
The reason for this is malfunction of the measuring device.
It is quite difficult to detect: it is necessary to invite a specialist with professional equipment capable of accurately determining the values.
And the problem also arises in devices that regulate the heating system automatically.
Features of the Navien boiler
In these units, the problem most often lies in leaks, especially when using fluids with a high glycol content. Antifreeze is very fluid, so it penetrates into the smallest cracks. Sometimes they are not easy to detect, so it is recommended to invite specialist, who will carefully check all the piping. Any leaks found must be corrected, then the expansion tank must be refilled and the pipes must be cleared of air.
And also the pressure decreases slightly as cooling of the coolant. Usually, after turning on the boiler, this problem is solved by itself. If the fluctuations are significant, diagnostics are required. The latter may lead to repair or replacement of equipment.
To fix it, it is enough to perform the actions similar to those described above. In rare cases, if it is impossible to solve the problem, you will have to purchase and install new heating device.
Photo 1. Wall-mounted gas boiler model Deluxe 13A, open combustion chamber, manufacturer - "Navien", South Korea.
Why does the pressure in a wall-mounted boiler rise?
In rare cases, a situation arises where the pressure gauge readings suddenly increase. twice as much. This may be related with one of three factors:
- The meter is broken and shows incorrect numbers.
- Make-up tap cannot withstand the pressure and starts dripping.
- Secondary heat exchanger out of order.
The problem is more noticeable near the drain valve. If the device starts behaving unusually: throwing out some water along with the air, most likely the pressure in the system is increased. In this case, you need to look at the readings manometer.
To solve the problem opens Mayevsky crane on the radiator and the pressure is dropped to normal. Then the readings are observed for some time: if they grow, then the problem is not in the measuring device.
It is recommended to tighten the feed tap more. If nothing has changed, you should read operating manual. It describes the hydraulic circuit that needs to be studied.
Useful video
Check out this video on how to repair a gas boiler.
Summary: Diagnostics of the home heating system
A problem detected in time is easy to fix. It will also reduce repair costs: any losses will be smaller before a serious accident. Periodic diagnostics — the key to long-term operation. To carry it out, you should invite a heating or water supply specialist.
