Ravenheat boiler problem with hot water

[NickB_99]

Hello all

Staying at my brothers at the moment and he is having trouble with his Revenheat combi boiler with the hot water supply.
Not sure which model it is (it didn't look obvious on the front)
Central heating is fine, but the hot water is not working every time.
The boiler is sited upstairs and can get lukewarm water from the bathroom taps. But downstairs in the kitchen it stays stone cold.
Is there a valve or something that could be sticking?
If so, is it possible to free it (removal, cleaning etc) or is it a replacement issue?
Apologies, don't really know my way round a CH system well!
He has got BG homecare, but I'm a bit reluctant to get them in until I've done some research.

Thanks.

 

[Agile]

You must be a newbee if you want to try fixing things for a relative and particularly when he has plumbing cover anyway!

 

[NickB_99]

You must be a newbee if you want to try fixing things for a relative and particularly when he has plumbing cover anyway!

True!
I'd hate to get them in and they tap something and it starts working again leaving me very embarrassed!

 

[Agile]

When relatives are involved its best to have nothing to do with it.

 

[flameport]

and when paying substantial sums of money for BG homecare, it's best to make full use of it when something breaks.

 

[NickB_99]

Point taken. Will get him to call BG.
Thanks for the prompt replies.