dbroms wrote:

We have just had a new worcester bosch system boiler fitted to a fully
pumped system. In the night we heard lots of noise from all the pipework and
the radiators so i went in the loft today to check something and found the
header tank which tops up the system has quite hot water in it !!

is this normal? i suspect not

It can be quite normal. The header tank is in fact a feed and expansion
tank. So not only does it feed water into the system when required, it
also exists to allow the water in the system somewhere to expand as it
heats up. Hence when operating you would expect the content of the tank
to be at least worm.

what could this be caused by?

see above, and also in your case "pumping over".

Does you pump have a speed selection switch on it? If so what speed is
it running at? If not already the slowest speed have you tried lowering it?


--
Cheers,

John.

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