Halstead Aces High problem - can anyone help?

[dybeck]

We have a Halstead Aces High combi boiler.

Every time we run hot water (or switch on the central heating), it burns for a few seconds, then the pressure gauge fluctuates rapidly and it switches off (and the lockout LED switches on).

The pressure looks to be stable (at 1 bar) when it's not in use.

Prior to this, the hot water has been slightly erratic (with taps running hot and cold).

We recently had the mains intake valve replaced, although I'm not sure how relevant that would be.

Can anyone help?

 

[Rob]

Sounds like a faulty pump.

 

[dybeck]

Is that a big/expensive job to fix/replace?

Is there anything I could check to test whether it definitely is the pump?

 

[Rob]

Remove screw from the front of pump (have rag ready for small amount of water) see if its turning with screwdriver or use screw driver to free it up by turning shaft.

 

[dybeck]

OK thanks for the advice...

Sounds like something I shouldn't be tampering with...

I guess I'll have to call someone out