"sro" wrote in message ...
"Mayur" wrote in message
om...
Over the past couple of days our valliant boiler has developed a
strange problem. When the ch comes on in the morning and the hw is
being used at the same time, some how water is getting into the ch
system and the pressure in the ch system goes upto about 4 bar and
then starts overflowing via the over flow pipe, at the same time the
boiler is making a funny noise.
What we have been doing when this has been happening is reducing the
pressure by opening the ch drain valve and once we have done this,
then its OK and continues to work.
We have had problems in the past with the boiler, its started off when
the pilot light kept going out and that sorted itself out, then its
was the rads getting hot when the ch system was off ? the only part we
have changed since having the boiler is the diaphram. I changed the
filler loop just the other day but that didn't help, could this be the
diverter valve ?

How about the pressure vessel - if the diaphram splits and you top it up you
can get very high pressures.
I had exactly that with a Worcester a few months back.
Incidentally, it doesnt take long to screw the overflow valve up when the
system goes over pressure.

Steve

Sorry folks but that should read Vaillant turbomax 828