A well-functioning boiler is essential for a warm and comfortable home, but if your boiler pressure is too high, it can cause serious issues. High pressure can lead to leaks, system damage, and even complete boiler failure. If you’ve noticed your boiler’s pressure gauge creeping up, don’t worry – we’ll walk you through the possible causes and how to fix it.
What Is the Correct Boiler Pressure?
Most modern boilers should have a pressure reading between 1 and 1.5 bar when the system is cold. When the heating is on, it might rise slightly but should generally stay below 2 bar. If your boiler pressure is exceeding 2.5 to 3 bar, it’s too high, and action is needed.
Why Is My Boiler Pressure Too High?
There are a few reasons why your boiler pressure might be above normal:
- Overfilled System – If too much water has been added while repressurising the system, this can lead to excessive pressure.
- Faulty Pressure Relief Valve (PRV) – This safety device releases excess pressure, but if it’s malfunctioning, the pressure will continue to rise.
- Expansion Vessel Issues – The expansion vessel absorbs extra water volume when heated. If it’s faulty, pressure can build up too much.
- Limescale or Debris Blockage – If there’s a blockage in your system, it could be causing water pressure problems.
- Continuous Water Supply from Filling Loop – If the filling loop isn’t closed properly, water will keep entering the system, raising pressure levels.
How to Reduce Boiler Pressure
If you’ve checked your boiler and found the pressure is too high, here are some simple steps to reduce it safely:
1. Bleed Your Radiators
Trapped air in your radiators can cause pressure fluctuations. Use a radiator key to release excess air – this might help bring your boiler pressure back to a normal level.
2. Check the Filling Loop
Ensure the filling loop valves are completely closed. Sometimes they may be slightly open, allowing a continuous flow of water into the system.
3. Release Water from the System
If the pressure is still high, you may need to manually release some water. Locate the drain valve (usually found near the boiler) and attach a hose to let out some water until the pressure drops to a safe level.
4. Inspect the Pressure Relief Valve
If your boiler pressure frequently rises, the pressure relief valve may need replacing. This is best left to a professional heating engineer.
5. Call a Heating Engineer
If you’re unsure about handling high boiler pressure or suspect a faulty component, it’s always best to seek expert help. An experienced heating engineer can diagnose and fix the issue quickly and safely.
Preventing High Boiler Pressure in the Future
To avoid future problems, consider these preventive measures:
- Monitor your pressure gauge regularly to spot changes early.
- Bleed your radiators annually to remove trapped air.
- Service your boiler annually to catch potential issues before they become serious.
- Check for leaks around the boiler and radiators, as even small leaks can impact pressure levels.
When to Seek Professional Help
If your boiler pressure keeps rising despite your best efforts, it’s time to call a professional. Unchecked high pressure can cause damage to internal components, leading to costly repairs or even the need for a full boiler replacement.
At Henri Taylor, we offer expert boiler repair services to diagnose and resolve pressure issues efficiently. If you’re experiencing persistent high boiler pressure or need general maintenance, don’t hesitate to contact us today for a reliable and professional service.
