Maintaining your boiler pressure

How to repressurise your heating system with a keyless filling link

Try using this repressurisation method if you see a blue lever inside the boiler, once the cover is removed.

• Firstly, you will need to remove the bottom cover.
• Locate the black manifold with the blue lever, which is normally on the right-hand side.
• Pull the lever down; you will hear the sound of water passing through, this is completely normal.
• Check your pressure gauge.
• Release the lever when the pressure gauge reaches between 1-1.5 bar.
• Finally, replace the bottom cover.

[Image: Hand operating a blue lever on a boiler manifold]

Watch our handy video on how to repressurise your heating system with a keyless filling link.

How to repressurise a heating system with an external filling hose

If you have an external filling hose, this option is the correct repressurisation method for your boiler. The hose may be underneath your kitchen or utility sink or elsewhere in the property.

• On one of the copper pipes, there should be a valve with a cap on. Remove the cap and let it hang off the pipe.
• Attach the end of the hose to this pipe. Next, open one of the levers on the valves.
• Open the second lever slowly; you should hear water passing through.
• Check the pressure gauge during this process.
• When the pressure gauge reaches between 1-1.5 bar on the dial, turn both levers so they are horizontal to the pipe.
• Unscrew the hose from the valve.
• A little water may come out, but this is completely normal. Make sure you have an old rag, or some kitchen roll ready.
• Finally, replace the cap.

[Image: Hand connecting a hose to a valve on a copper pipe]

Watch our how to repressurise your heating system with an external filling hose video for more details.

How to repressurise your heating system with an internal filling key

This method of repressurisation should be used if you have a key inside the bottom cover of your boiler or if you can't find your key. They're available from plumbing merchants and retailers such as Screwfix and Amazon.

• You will need to locate the manifold with the nut on it.
• Look for the padlock symbol on your manifold and insert the key.
• Try to push it firmly but not too hard, turning it 45 degrees to the left, towards the locked padlock symbol.
• Continue pushing; it will rise slightly further into the manifold. This is normal and is to ensure a tight seal. It should now feel locked in place.
• Then turn the nut to the left. You will hear the sounds of water passing through, which is normal.
• Watch the gauge and turn the nut off when it reaches between 1 and 1.5. Don't worry, if you go too far, then bleed your radiators.
• When the heating system is on, this will rise but will return to between 1 and 1.5 when cool again.
• Turn the key 45 degrees and pull it out firmly. A few drips of water will come out; this is nothing to worry about.
• If it continues to drip, you may need to tighten the nut a little more.
• Finally, put your key back into the bottom cover and replace.

[Image: Hand inserting a key into a boiler manifold with a padlock symbol]

Click here to watch our how to repressurise your heating system with an internal filling key video.

Need Further Assistance?

If you haven't managed to resolve the issue yourself, call Worcester Bosch on 0330 123 9559.