Boiler Cuts Out Ferroli Optima 901

[jg1975]

Please Help !!!

I have a ferrroli optima 901 boiler and have problems with it. When the central heating is switched on it runs for about 15-20 mins and then cuts out causing no boiler function (the radiators start to cool and the ingition does not light the boiler for hot water) My plumber recently replaced the limit thermostat but this did not solve the problem. he now suggests the pump could be faulty causing hot water to remain in the boiler therefore shutting it down. I am not convinced though as the return to boiler seems as hot as the feed and the pump is circulating when removing the centre cap any advice.

Thanks Corgiman answer Yes it does lockout have to isolate mains supply and switch on again. is the overheat stat the same as the limit stat?
Thanks

 

[corgiman]

the return will probably be with a couple of degrees of the the flow mate (unless you live in a huuuuugre place of course) so dont worry about it

Pump is definatley working, and not just because its spinning, but because your boiler is not making a noise like a pigeon has got in it and the return is hot. so your engineer is wrong methinks

Does the boiler go to lockout?? if so sounds to me like the Overheat stat is suspect