How I do I reduce the pressure on a combi boiler system?
Posted on May 31st, 2010 by admin
I repressurised the system yesterday and forgot to turn the valves back again. As a result the pressure is now between 2 and 3 when cold and almost at the highest level (4) when I turn the heating on. What can I do to reduce the pressure?
Thanks for your help in advance.
Open a bleed valve on a rad and draw off excess water that way. Do it when the boiler is cold.
May 31st, 2010 at 9:52 pm
2 things
1. let the boiler do it for you
2. remove some water form the lowest radiatior from bleed tap
But i don’t think that 4 is too high, what do your instructions say, mine is 2 cold and 3 when hot.
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May 31st, 2010 at 10:05 pm
Most combi boilers have a pressure relief valve that operates at 3 bar so i should get it checked if its going up to 4 bar as it could be dangerous. open a bleed valve on a rad and drain some water into a bucket, if there’s a drain off valve open that to let some pressure out but be careful cause they have a tendency to leak if they haven’t been used for a long time. Bleed valve is probs best to use if you don’t have much experience.
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May 31st, 2010 at 10:36 pm
Hi You need to bleed water out of the system. This can be done at the most conveniebt radiator. If you look at a radiator at the top left or top right corner there will be a bleed nipple. You need a small rad valve key to unscrew the bleed nipple 1 or 2 turns (anti clockwise). Have an old cloth or bowl to collect the water that will come out. It may be discoloured so don’t pick the radiator with a new lounge carpet. If your system is hot allow it to cool down before starting, the water coming out could scald. Bleed a cupful out then recheck the pressure gauge. Repeat until you are in the green area of the gauge.
Hope this helps. PS radiator keys can be bought at B& Q type outlets and should only be about £1.
Cheers Dave
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May 31st, 2010 at 10:46 pm
GW These boilers have a safety release valve set to 3 bar, not only is the questioners boiler safety faulty, but so is yours, both pressure relief valves should be replaced.
References :
Heating engineer for http://www.familygascare.co.uk
May 31st, 2010 at 11:06 pm
Open a bleed valve on a rad and draw off excess water that way. Do it when the boiler is cold.
References :
Plumber.