The nominal pressure in the system ensures the normal circulation of the coolant and the pressure in the valves. But what if the pressure drops in the double-circuit boiler? Why is this happening? Main reasons:
- incorrect installation
- mismatch of boiler power to your pipeline,
- flow,
- radiator damage
- interruptions in gas supply.
Consider how to raise pressure and what to do when the boiler does not hold it.
Varieties of pressure
Why does the pressure drop in the wall device? To begin with, we will understand what types are and how they affect the operation of technology.
- Static The higher the height, the higher the performance. With each meter there is an increase of 0.1 bar.
- Dynamic. Forced operation of the pump creates a nominal head in a closed system.
- Working. Includes the two options above.
- Excessive. It is determined by a manometer as the difference between atmospheric and recorded.
- Rated. The one indicated by the manufacturer in the documentation for a particular model.
- The maximum. The maximum allowed to avoid breakdowns and accidents.
- Pressure testing. Used in production for testing equipment.
In the heating circuit, the readings are measured by atmospheres. They may vary; it is important that the value does not exceed the allowable maximum and minimum thresholds. A low value is only possible when the coolant is pumped into the circuit. In other cases, it should not deviate from the norm.
Pressure control in a gas boiler
All modern heating equipment is equipped with control sensors. A pressure sensor monitors normal operation. In the event of a deviation from the norm, it sends a signal to the control module, which is why the boiler is blocked. Additionally, an error code may appear on the display.
What pressure should be? A pressure gauge helps to track values. The mounted unit "Bosch", "Ariston", "Navien", Baxi, installed in the house, supports values from 1.5 to 2 atm. A drop in performance is observed only in systems with forced fluid movement (pump).
How the equipment works
Under normal conditions, work proceeds as follows:
- Sensors record the temperature of the coolant. If an outdoor thermostat is installed, the burner will automatically light up and heat up.
- With increasing temperature, pressure rises. When heated, the water expands, so an expansion tank is provided to discharge excess coolant. The safety valve also dumps excess into the sewer.
- If a malfunction occurs, too much water is drained. As a result, the pressure drops.
- As soon as the temperature reaches the set value, the boiler switches off.
More about the operation of the expansion tank:
- The tank consists of two parts, which are divided by a diaphragm. Nitrogen is in one cavity, and excess fluid accumulates in the other.
- The coolant fills it as much as the difference in the values of the system and nitrogen.
- As soon as heating stops, nitrogen pushes water out of the cavity by deforming the membrane.
Why did the water pressure drop
What affects the performance in the circuit:
- The installation height of the housing, as a result - the height and length of the pipes.
- The effects of liquids on pipes and other elements.
- The construction of the main tracks.
If autonomous heating is installed in your house, then the norms depend on:
- Models of the boiler, pipeline paths.
- Mounting locations.
- The number of floors in the building.
- The characteristics of the outer pipe.
Further we will consider the reasons which are not connected with installation. If the device relieves and does not build up pressure, it may be an internal breakdown or external factors.
System leak
You add coolant to the circuit, but the pressure is still low. If the batteries heat up well, moisture evaporates quickly, making it difficult to locate the leak. Take a dry napkin and go through all the pipe joints, joints. Look, maybe there are puddles under the radiators.
If a leak cannot be detected, use a compressor.
- Disconnect radiators from the heating device.
- Drain all liquid.
- Connect the compressor to the taps.
- Bleed the circuit with air.
- You will hear an extraneous sound in those places where there is damage.
- For sealing use a plumbing tow or sealant.
Are your radiators built into the wall? Then consult a specialist. They will check with a thermal imager. You will have to open the damaged area and carry out repairs.
Incorrectly selected boiler - the power does not correspond to the established parameters of the pipeline. Therefore, it constantly drops and does not hold pressure.
If the values fall quickly, the reason may be expansion tank. At the same time, you fill up the coolant every week, but it becomes less and less, although there are no leaks. Also there is a discharge of pressure in the mixers.
How to score and increase indicators:
- Turn off the water supply valves.
- Drain the circuit completely.
- Open the union on the expansion tank (RB) and fix the numbers.
- Pump air until all water has escaped.
- Bleed the air and repeat. Make sure that the needle on the pressure gauge does not exceed 1.3 bar.
- Open the taps and fill the fluid.
If pressure drops and does not rise after the procedure, inspect the membrane for damage. Replace if necessary.
Heat exchanger malfunction. After checking the pipes and connections, no violations were found? Inspect the radiator for damage. A large accumulation of scale on the tubes leads to frequent flushing with reagents. From this material wears out quickly, cracks appear.
The bithermal unit cannot be repaired due to the design. Replacement required. If a tubular radiator is installed, dismantle it. Fistulas can be detected by green spots on the surface. Dry the device, clean the damaged area with sandpaper. After soldering, use a soldering iron or a torch.
Unfortunately, after repair, the unit will not last long. Therefore, sooner or later it will be necessary to change it.
Problems with tap refill. When leaking, the valve leads to a constant pressure drop. How to add coolant to the system? Only replacing the part will help.
Three-way valve problems. In dual-circuit devices, the valve is used to switch flows from heating to hot water supply. Clean the valve; scale and debris may interfere with its operation.
Airiness. To determine that an air pocket has appeared in the batteries is not difficult. This is clear from gurgling sounds where water collides with air. Do this:
- Record the pressure gauge.
- Turn off the technique.
- Place a container under the Mayevsky tap and open its valve.
- You will hear how the air goes, liquid may drip. Wait until the hiss stops.
- Turn on the water and dispense it until the pressure gauge needle reaches its initial position. Turn off the taps.
- Start the boiler and listen to the work. If sounds are heard again, repeat the procedure.
Gas problems in the trunk
Failures in the fuel supply lead to heating disturbances and boiler blocking. For what reasons interruptions occur:
- Clogged gas fittings: filters, nozzles, hose.
- Faulty or clogged gas valve.
- Fuel leak. Turn off the valves and call the gas service.
As you can see, problems with the operation of the boiler arise both for internal and external reasons. If you are unable to locate the problem, call the wizard. He will diagnose the system and fix the breakdown.