Boiler cutting out

My Combi Boiler (Alpha 240p) is playing up.

When we switch the shower or tap on initially the boiler ignites and we receive hot water. However, after a about a 30 seconds to a minute the boiler cuts out and the water goes cold. The Pilot Light remains lit though.

I tried switching the heating to 'on', to see if the boiler ignites and it does, but again cuts out after 30 seconds to a minute.

I am not sure how long this boiler has been fitted as it was here when we moved in 5 1/2 years ago. We have had a few previous problems with it and I am aware that Alpha Boilers are known to be utter tosh, so maybe cheaper in the long run to get a new one!?

I would be grateful if someone could help with a possible diagnosis for the problem we're having.

Cheers in advance.

Matt

Likely cause is the thermistors, change both, one on DHW side and the other on CH side. Now you are going to ask how that is done, aren't you?

Thank you for the quick reply.

Don't worry I won't be asking how to do it - I'll just get a Corgi in.

Me and DIY don't go together!