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Steps on how to Re-pressurise Your Boiler

Steps on how to Re-pressurise Your Boiler

Re-pressurising your boiler every now and again is an important maintenance job that helps to keep your boiler healthy. Whether you have a system, a combination or a combi boiler, re-pressurise it regularly and you’ll be heating your home more efficiently, extending the life of your boiler and helping to cut down any potential engineer costs. 

If you find your central heating system isn’t working as it should, it’s possibly due to a loss of water pressure. But before you pick up the phone to call out a professional, why not find out how to re-pressurise your boiler yourself?

To increase the pressure in your system, you’ll need to use a filling key or filling loop (filling hose), depending on the age and type of boiler you have. 

Re-pressurising your boiler using a filling key

Step 1

It’s important to switch your boiler off before re-pressurising it. If possible, let it cool down for 4 to 6 hours. 

Steps on how to Re-pressurise Your Boiler

Step 2

Carefully pull out the tray underneath your boiler and remove the key attached to it. You may find the key is secured to the tray with a clip. If so, unclip it to remove. 

Steps on how to Re-pressurise Your Boiler
Steps on how to Re-pressurise Your Boiler

Step 3

Next to the square manifold nut, you’ll find the key manifold keyhole. Insert your filling key into the key manifold. 

Steps on how to Re-pressurise Your Boiler

Step 4

Turn the key approximately 45 degrees to the unlocked position. 

Steps on how to Re-pressurise Your Boiler

Step 5

As the pressure begins to rise, the arm on your boiler’s pressure gauge will begin to move up. Turn the manifold nut clockwise when the gauge reaches 1.5 bars. Keep an eye on the gauge to make sure it settles at this pressure.  

Re-pressurise Your Boiler

Step 6

If the arm moves into the red section on your gauge, don’t panic! Turn the release knob on a nearby radiator and this will quickly lower the pressure on your boiler. 

Re-pressurise Your Boiler

Top Tip! 

If you need to do this, take care not to be too close when turning the release knob on the radiator — the release valve will emit hot air. 

Step 7

When you’ve turned both the manifold nut and the manifold key back to the locked position, remove the filling key and put it back in the tray underneath your boiler. 

Re-pressurise Your Boiler

Step 8

Switch your boiler back on. The pressure may fluctuate slightly at first, but it should settle within a minute or two.  

Re-pressurising your boiler using a filling loop 

Step 1

Switch your boiler off and allow 4 to 6 hours for it to cool down. When your boiler has cooled, check the filling loop hoses are secure (they may need tightening). 

Re-pressurise Your Boiler

Top Tip! 

A radiator, expansion tank or pressure relief valve leak could also cause a pressure drop, so it’s worth checking these things, too. 

Re-pressurise Your Boiler

Step 2

Open the filling valves. These can be unlocked by tap handles, or with a screwdriver, and will be found near to where the filling loop hoses connect to the boiler. As you turn the valve counter clockwise, you should start to hear water. 

Re-pressurise Your Boiler

Step 3

When the pressure gauge on your boiler reaches 1 bar, it’s time to close the valves. 

Re-pressurise Your Boiler

Step 4

When the pressure on the gauge has settled at 1 or 1.5 bars, switch your boiler back on. 

Re-pressurise Your Boiler
Re-pressurise Your Boiler
Re-pressurise Your Boiler

Once you’ve topped up the pressure on your system, your boiler should be working well — successfully heating your home and giving you plenty of hot water. But if it begins to lose pressure again, or you don’t have the time to give it a go yourself in the first place, call a boiler repair engineer. 

Need the peace of mind to know you’re protected against any sudden, expensive boiler repair costs? 

With cover plans starting from as little as £11 per month, YourRepair gives you access to over 5000 gas safe engineers across the UK, a UK-based call centre open 24 hours a day and the option to fix your cover price for 3 years — no matter how many claims you make. And with instant protection and an annual boiler service and safety check included, you’ll never need to worry about your boiler again

So, if you don’t have the time to work on your boiler the next time your water pressure drops and you don’t fancy any unexpected repair costs, call our friendly team on 0330 223 4422, to find out which of our home and boiler cover plans will work best for you. 

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