additional information

i have just watched the system and noted as soon as the demand for the
heating goes off , the pump seems to flow all the hot water into the header
tank in the loft for about 5-10 seconds. The tank then seems to go back to
its correct level.

Is it when the valve is changeing state?

if so, what can i do?


"dbroms" wrote in message
...
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

what could this be caused by?

apart from the noise which only seems to happen at night, everything seems
ok

cheers

Daz

ps. it has just been converted to a standard Y plan system because we
had no independant control over the hot water so they added a 3-way valve