The boiler keeps shutting down or not starting and shows error code 04 - insufficient pressure or flow, but the pressure is OK. If I press reset, it then works. I have a BG contract and they have been trying to fix it for two weeks and seem to have replaced almost every boiler part including the pump. They now say they think there is debris in the system and that it needs a power flush - at £700. Has anyone come across this problem or have any ideas what's wrong?

Bruce, April 2008

I have a code fault 04 and the pressure is below 1 what do i do?

Alan, May 2012

That guy was talking rubbish- 04 code error has two meaning 1- insufficient flow-but if the pressure is good goto fault 2. The condenser flow at the back has to be gravity fed and if the plastic flow pipe is not below and allowed to run away without any loops in it the boiler will stay up with error code 4 until the condensing water can escape.

Allan Clark, September 2008

Yes, sounds like your system may need fushing and treating, have come across it many times, I know it sounds like a lot of money, but if the system is sluged or scaled up, no matter what you spend on parts to fix the boiler, in a number of months you will be in the same situation.

A quick check, if you bleed a ltiile water from the air vent of one of your rads and is is black-ish (sludge) or reddish (rush) your system needs flushing and treating (a good power flush should take between 8 - 10 hours to do (make sure you get your monies worth)

Y, April 2008