In this article, we’ll explain boiler pressure, why it’s important, and what it means for the safety and performance of your heating system. In addition, we’ll go over how to check and adjust your boiler pressure to keep your system running smoothly. So, whether you’re a homeowner or a tenant, keep reading to learn everything there is to know about boiler pressure and what it means for your home’s heating system.
What is Boiler Pressure and What Does It Mean?
A well-functioning boiler is essential for central heating and hot water. When it comes to the continued operation of a boiler, boiler pressure is an important factor to consider. The water pressure within the system influences the flow and heat distribution throughout the home. . When the heating is turned on, the pressure gauge on the boiler will indicate the pressure level in the system, which should be around 1.5 bars. The precise recommended pressure level will be determined by the boiler manufacturer.
What should the pressure be on when the boiler is turned on
The pressure gauge on a boiler should read around 1.5 bars. This is the typical pressure range for most boilers, though the exact pressure level recommended by the manufacturer may differ. The pressure should never be higher than 3 bars. It is important to consult the boiler manufacturer’s instructions for the recommended pressure level for your specific boiler make and model. A pressure gauge is typically a digital or mechanical gauge mounted on an appliance. If the pressure drops too low or rises too high, the boiler will shut down automatically.
Normal Boiler Pressure When the Heat is Turned Off
The boiler pressure should be between 1 and 1.5 bars when the central heating is turned off. At all times, the pressure gauge should be above the manufacturer’s lower limit. Check the boiler manual for specific recommendations for your model, as these may differ depending on the manufacturer. If the pressure gauge needle falls below the lower limit, this could indicate a problem with the system and should be investigated by a competent person or a heating engineer.
What Causes a Change in Boiler Pressure?
Understanding why the boiler pressure changes is essential for knowing what to do if the pressure deviates from the normal range. When the heating is turned on, the boiler pressure rises due to the water expanding as it heats. The hot water expands as the temperature rises, causing the pressure to rise. Even if the pressure continues to rise above the upper limit for the boiler model, this is a normal occurrence and should not be cause for concern. To compensate for this increase in pressure, boilers are fitted with an expansion vessel which allows for this process to occur.
What Should You Do If Your Boiler Pressure Is Too High?
There are several possible causes for excessive boiler pressure. If you recently topped up the system pressure and inadvertently added too much pressure, you can easily correct this by bleeding a radiator to reduce the pressure within the system. If the pressure is greater than 2.5 bar, it is recommended that the pressure be reduced before using the appliance. If the issue persists, it may be the result of a faulty external filling which could be bypassing excess water into the system. The issue may also be caused by a faulty expansion vessel or one that is not adequately topped up with air.
What Should You Do If Your Boiler Pressure Is Too Low?
If the system pressure is low, it indicates that there is insufficient water in the system. This is typically caused by a leak, which most commonly occurs near plumbing fixtures. Check for damp spots or rust marks around your radiators, as well as signs of leaks on walls or ceilings which could indicate the source of a leak. The boiler can be repressurised using the system filling loop once the leak has been repaired. If a leak cannot be found, it may be due to a faulty boiler, and the system should be inspected by a qualified engineer. If a leak has been repaired but the boiler pressure remains too low, the pressure relief valve may be stuck and should be replaced by a qualified engineer.
Is high boiler pressure dangerous?
Modern boilers have safety valves and controls in place to protect the users and the components of the boilers from high pressures. Combi boilers are fitted pressure relief valves that are designed to open up around 3.5 bars and remove water from the system in order to drop the pressure. Combi boilers are also designed to send signals to the circuit board (PCB) and stop the boiler from operating until the issue has been resolved
What should I do if my combi boiler pressure is rising to 3 bar?
If the boiler pressure is consistently rising to 3 bar or higher it may indicate a problem with the expansion vessel, which should be inspected by a qualified gas engineer. In the meantime, avoid using the heating system until the problem is resolved, as high pressure can strain the system and potentially damage the pipes, radiators, and other components.
What is the purpose of a combi boiler expansion vessel?
A combi boiler’s expansion vessel serves two important functions:
To absorb excess pressure:
A combi boiler rapidly heats water within the heating circuit. Water expands as it heats up, and this increase in volume can cause an increase in pressure within the system. The expansion vessel acts as a pressure buffer, absorbing excess pressure and ensuring the system’s stability and safety.
To keep the system pressure constant:
The expansion vessel is pre-charged with air at a predetermined pressure, and this air pressure aids in keeping the system pressure constant. If the system pressure drops due to a leak, for example, the air in the expansion vessel will be compressed, keeping the overall pressure in the system constant.