Combi Boiler, 2 timers?

[samsunguk]

Hi. I have a combi boiler, Halstaed Ace, with a built in timer and also another Potterton EP4002 next to it with a seperate thermostat.

I am having trouble getting the central heating to stay on, if I switch the whole lot off for an hour then back on I can get the heating to come on for 5 - 10 mins max and it will go off until I switch it all off again.

I have just had a plumber look at it and said it is probably something to do with the timers, but he wouldn't go in the boiler because he isn't CORGI registered.

Both timers are set for max temp and set to continuous.

Any help would be greatly appreciated as to what you think the problem may be.

Regards,
Sam.

 

[gas4you]

You need to be able to check at the boiler call for heat terminal that there is 240VAC when the boiler goes off.

If there isn't it is indeed that timer/s if there is it is a boiler fault.

Don't attempt this check unless you are competent and confident testing live mains electric

Refreshing to hear of someone not touching your boiler and admitting he is not gas registered

 

[SEP]

I have an oil-fired Wallstar Combi and have just discovered that it was probably put in with the wrong size piping for what is (I'm told) a closed, pressurised system! My radiators do not get more than warm before the boiler switches off and I have been told this is because the pipes are too narrow (15mm) so that, having heated the water, the pump cannot get the hot water around the system quickly enough, so it overheats and switches off. Once the water has cooled, the boiler will switch back on again, and the whole thing starts again.
So it may not be your boiler that is the problem.........

 

[bengasman]

a combi needs one timer and one roomstat; ditch the rest