Help needed

[TomTom01]

Hi,
I have a valiant eco tech plus 824 that has an issue. When I run the hot water, it runs hot for a minute then goes cold. The burner cuts out and won’t cut back in. If I run the hot tap on half, I get constant hot water. My engineer came out and was confused, rang valiant tech support and they had no idea. Said it must be the PCB. That has been changed and still not fixed the problem. Any ideas what could be the issue?

Cheers in advance

Tom

 

[Dan Robinson]

Clogged hear exchanger.

 

[TomTom01]

Thanks Dan, is it easy enough to change? Looks ok to drain and remove, just not sure about re-filling and getting the air out.

 

[Dan Robinson]

You need to be Gas Safe registered to do this.