Combi Boiler- variable water temperature Help and information on all topics relating to your central heating, air conditioning and ventilation issues.

[rdelisle]

Hot water changes temperature from hot to warm and back to hot etc.
Is there a common cause please?

[toneyt]

sounds like scaled heat exchanger,what boiler is it?

[rdelisle]

Hi, its a Baxi Combi 80e

[toneyt]

commonly the domestic heat exchanger will scale up/block does the boiler fire up then off ,cycling on and off as this can indicate the boiler reaches temp internally then cuts as it senses too much heat,but the water temperature is moderate,
secondly check too see if the central heating pipes heat up at the bottom of the boiler as this could be the diverter valve letting by,in this case the boiler would remain on and not cycle on/off
T

[rdelisle]

Thanks very much. Where would I go for info on descaling. The Boiler Manual is curiously silent on problem solving.

[toneyt]

i wouldnt bother descaling get a new one and fit a scale reducer to help slow the problem down for the future

[rdelisle]

OK.
Thanks for all your help.
Much appreciated.