It is a Chaffoteaux Combi 80 and in hw or heating mode it fires for about 5 seconds then goes out it and does the same again 30 seconds later and keeps on doing it. It is not going to lockout.The service manual has been lost.

David Murphy, January 2010

I have a very similar fault, but this only happens on the central heating side, not on the water side. By doing some very basic fault finding, it turns out to be the flow switch. how to check it (I am not qualified in any way on boilers, but am an electro mechanical engineer). isolate from the mains, dont just switch it off on the front. remove the white cover, and then drop the control panel down. remove the plug with 2 red wires going to it, and using a paper clip, short out this connector (its not ideal, but is low voltage), secure it away from any metal (tape it to other wires), and then switch the mains on. switch the boiler on, and test the heating. Mine now works perfectly, although i will be replacing this switch. for info, it may not be the best boiler, but mie has now been working for 12 years, and this is the second fault it has had, the other way a 3 way valve failure.

Paul, January 2010

Its the make apprently I've been told by 2 independant engineers that they are the worst make of boiler to have and been advised not to spend a penny on them its not worth it 4 of my neighbours have the same these were put in when the houses were built they have already replaced their boilers and one was less than 2 years old its french and its crap
Minen has now worked for the past two weeks inconsistent on faults occassionaly it does fire up but not for that long waiting for new boiler to be installed on Friday can't wait to see the back of this old crap thing

Sharon, January 2010