My combi boiler regularly loses pressure (down to zero in a week). Also, at times, when the pump is running, it sounds like a jet engine taking off, but at other times is perfectly quiet running.
Mine has the same problem, down to zero within 4 days. Been told new expansion vessel needed as water comes out of the vessel when attempting to pump it up to 1 bar pressure.
Tim
April 2008
the pump prob makes a noise when your low on pressure .. check for leaks on the system and check the relief pipe outside for water dripping out of it
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