System boilers do not have header tanks

mine has definately got a header tank. The valve is a honeywell 3 position
diverter valve. The tank has a built in header tank that supplies cold water
to be heated up and the other header is in the loft which tops up the sealed
heated water that flows through the coil in the tank unless i have it
totally wrong.



"Doctor Drivel" wrote in message
reenews.net...

"dbroms" wrote in message
...

We have just had a new worcester bosch system boiler fitted to a fully
pumped system.

System boilers do not have header tanks.

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

Check that air is out of the system.