Combi boiler - tepid water unless central heating running.

[Geoff Pearson]

The hot water never gets piping hot but if the central heating is running too, the radiators are almost too hot to touch and the hot water gets that way too. Is this the diverter valve at fault - do I need a man in? What else might it be?

Geoff

[John Rumm]

What make / model of boiler?

What power output?

Does the boiler fire up and keep running if you use just the hot water?

Does the temperature increase if you reduce the flow rate?

[Geoff Pearson]

Does the boiler fire up and keep running if you use just the hot water? ------------------ Yes

What make / model of boiler? What power output? ------------------------------------------I will check and report.

Thanks for taking an interest.

[John Rumm]

Bonus question, if you keep the hot water running does the rad circuit heat up? (feeling the flow pipe out of the boiler should tell you).

[Geoff Pearson]

I will check and report - it is my nephew's boiler at the other side of the city.

[Geoff Pearson]

It is a Glowworm Compact Electronic - no rating marked. Need to do more testing of options..