Hot water problem, combi boiler at fault?

[Gavin77]

Think I paid £130 for the heater. I did work out all the costs before buying it cant remember exactly what it worked out at, but for me it was certainly worth doing. its 10kW and i think it gives about 8 litres per min.

Yes its fed from the cold water supply. With a dishwasher, its mainly used for washing hands and the odd dish. For small amounts of hot water it must be the cheapest way of heating it. But the main advantage is the convenience of having hot water without the 30 second warm up time.

 

[Gavin77]

Right, back to the original topic.

The problem is still tepid hot water out of the combi. Placing hands on pipes coming out of the boiler, then turning on a hot tap, and the central heating pipe is definately getting hot as well as the hot water pipe.

They have had a gas engineer round, who has looked at the boiler, measured the flue gasses, said its running at 75% efficiency and that the boiler is fine, and charged them £70 for his time. He has also said the central heating system is in need of a power flush.

Now the CH system may well need a power flush, but my issue is that I cannot see how this would affect the problem with the hot water. I still suspect its the diverter valve in the boiler. Could a gunked up central heating circuit cause a diverter valve to stick?

Can any combi boiler experts advise? Im very concerned that my folks are about to pay out £300 - £400 for a powerflush that I dont think is going to make any difference (But am more than happy to be proved wrong )

 

[nickso]

what boiler is it?

Was the diverter valve mentioned to him? It sounds like it is passing so get someone useful to change it. The state of the water in the heating circuit can then be checked when the boiler is drained down.

 

[Gavin77]

Its a Baxi combi boiler. Not sure of model, will have to ask them.

If the diverter valve isnt working, surely the only way the rads would be getting hot is with the CH pump running? Is it normal for this to run in a combi when the CH is off and hot water is being drawn?

 

[nickso]

Yes.

 

[misterdubya]

Blimey - still not fixed.