Halstead Finest Gold 07 Boiler problem

[LizC1974]

Our Halstead boiler keeps cutting out and switching itself back on when you run the hot water making the hot water alternate between hot and cold (not fun when you are in the shower!).
We have already had a plumber out who said it was the solenoid, so we bought a new gas valve but this did not fix the problem.
The CH is fine and stays on, it's just the water.
Can anybody help pls?!

 

[gas4you]

Don't know what 07 is, but I assume it could be overheat.

Sounds like you have the classic blocked plate heat exchanger.

This needs removing and cleaning, or, as I do, replacing.

Assuming it is the system side of it that has blocked, you should really consider flushing the heating system properly, other wise the new one will block again.

Don't know how he could have thought it was the gas valve

 

[LizC1974]

07 is just part of the GC number - I thought it may help!

Thanks for your help Dave, I will get it replaced and see how we get on!

Liz