Worcester combi boiler no heat until hit!

[Salluad]

Hello all,

My 10 year old Worcester Combi boiler has stopped working. The Power light is on. When the thermostat kicks in for the central heating, I can hear what I guess is the pump turning, but the boiler does not ignite at all. Water pressure is 1.0 bar (cold). Same result when a hot tap is opened, all the right kind of pumping noises, but no whoosh of ignition, and clearly no hot water. however a slight (physical) tap on the boiler casing and ignition! for a while..... then the boiler cuts out and needs another hit! running hot water while the flame is on will deliver hot water but as soon as demand stops (turn tap off) then no ignition again until another hit to the casing.

Any ideas?

 

[B.O.B DOLE]

you need to take the casing off and try it then

 

[Salluad]

Got the engineer coming tomorrow I'll ask him to try it without the casing on.

 

[Salluad]

Sorry about the delay in replying. Looks like the heat exchanger was at fault, according to the two engineers who came out, a build up of limescale was to blame!
Well it's been a month now and no problems to report so we will have to wait untill winter sets in to see if this realy was the cause.
Will be in touch to let you all know.

 

[megawatt]

Sounds like a loose stat cable to me