Low boiler pressure is one of the most common heating problems homeowners experience. If your boiler pressure keeps dropping, the system may struggle to circulate hot water through radiators effectively.
Fortunately, many pressure issues can be diagnosed and repaired quickly.
What Is Normal Boiler Pressure?
Most boilers operate best between 1 and 1.5 bar when the heating system is cold. If pressure drops below this level, the boiler may shut down as a safety precaution.
Common Causes of Low Boiler Pressure
Several issues can cause pressure loss in a heating system.
1. Water leaks
Leaks in pipework, radiators, or valves can gradually reduce system pressure.
2. Recently bled radiators
After removing air from radiators, pressure may need to be topped up.
3. Faulty pressure relief valve
If this valve fails, it may release water unnecessarily.
4. Expansion vessel issues
A damaged expansion vessel can cause fluctuating pressure.
How to Repressurise a Boiler
Many modern boilers have a filling loop that allows homeowners to safely increase pressure. However, if pressure continues dropping repeatedly, the underlying cause should be investigated.
When to Call a Heating Engineer
Persistent pressure loss usually indicates a mechanical issue within the system.
A qualified engineer specialising in boiler repairs in Aberdeen can check the system, identify leaks, and restore proper operating pressure.