Myson Apollo 30B-Cutting out

[notgotaclue]

Hi there, I have a Myson Apollo 30B boiler which has suddenly stopped working, I’ve noticed in the past that occasionally it didn’t fire up straight away when turned on but have never had any other trouble until now.

I have a fully pumped, balanced system.

It seems to only fire up when the boiler is cool, the 3 position switch clicks into position supplying live feeds to both the pump and the boiler simultaneously, however the boiler will cut out after a short while - seems to be directly related to how cool the boiler is to start with (it does this on both high and low settings). Even though there is still a live feed supplied (checked at the multi block connections behind the high/low thermo switch on the boiler), the pump continues to run and is working fine.
I think that it may be the thermostat??? How can I test this?
Can anyone help please?

[gas man]

sounds like your pump has failed this is a low water content boiler relies on a good pump the symptoms you describe could be the thermostat but i have seen this fault many times

[notgotaclue]

Thanks for the answer received, much appreciated. The symptom changed slightly inasmuch as one minute it would work a lot longer than another, then it wouldn’t fire up at all, unless left for hours to cool down, I bought myself a multimeter rather than the illuminating screwdriver/tester I was using and was able to test exact voltages, then disconnected the solenoid to check for continuity across the windings, sure enough when there’s no continuity the boiler won’t fire up. Just bought a new solenoid (£11.96).
Jobs a good un ta very much!