Inefficient Combi

14 Jan 2005
Reaction score
United Kingdom
I have recently moved into a 11 year old 4 bedroom detached house with a Ferolli Combi. The CH works OK, but when I turn on a hot domestic tap, the water runs cold for about 15 seconds (as expected) runs hot for 10 secs then cold again for another 15 secs before the hot runs constantly. Why the cold/hot/cold/hot sequence? I have noticed that the boiler takes 10 secs to ignite after the hot tap has been fully opened this normal?.......shouldn't it be instantaneous?..........can I adjust the timing?

Cheers all

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from your questions i would advise you have the boiler checked by a competent engineer and no you cannot adjust the timing yes it will run hot/cold/hot also a lot depends on pipe configuration/distance,when was it last serviced? :LOL: :LOL:
A fiver says it's scaled up. Probably a "combined" heat echanger so not simple to clean without a bit of kit.
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Chris - It won't be scaled up as our water is super soft!!!!!!!!!!!! even the kettle element is spotless.
Frenchie1 - Why do you think it could be the over heat stat?
it is not the o/h stat as that would affect the heating as well

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