Fixing Low Boiler Pressure

Posted on by Daniel, VHL

Boilers work incredibly hard to to keep us warm and provide us with hot water for washing, cleaning and heating, especially in the colder months. With all the work that they are required to do, it is hardly surprising, then, that they can encounter faults from time to time which hamper their efficiency.

Does My Boiler Have Low Pressure?

Boiler Pressure GaugeIf you notice that your boiler is not providing as much warmth or is taking longer to warm your home than usual, it could be a sign of low pressure.

There are steps you can take yourself to alleviate this issue below:

Check The Pressure Gauge

Each boiler will have a pressure gauge indicator, so by checking this you can determine if the problem is centred around this. If your indicator is showing low pressure, it could be because there’s a leak in your system. If a pressure drop is a regular occurrence, it could be an indication that you need an entirely new system, at which point you should consult an engineer.

DIY Repair

DIY boiler pressure fixTo fix your boiler yourself, you will need to consult the instruction manual that came with your particular model of boiler. There will be detailed steps that you need to take to fix the issue, but be aware that if you find yourself doubting your ability to solve the problem, call a professional engineer instead.

Often, if the pressure in your boiler is low, you will need to top up the level of water. You can do this by opening the inline valve with a screwdriver – do this gradually, while watching the state of the pressure dial. The dial should reach the appropriate level (1 to 2 bars) fairly quickly, so be sure not to leave the valve open for too long. The valve is usually closed when the slot for the screwdriver is at 90 degrees to the valve.


Once you have fixed the issue, test it by trying to turn your boiler on again. The boiler will only start if it has the correct pressure. If the system does not start, check the pressure again, but you should make sure that you are completely confident and knowledgeable about the boiler system, otherwise seek professional assistance before you try anything else.


About Daniel, VHL

VHL's Technician of the Year +Daniel Chambers View all posts by Daniel, VHL →