On 27 Oct 2006 03:05:25 -0700, wrote:

Hi, this is my first post so please bear with me :-)

I have a potterson conventional boiler in my kitchen (downstairs) and a
hot water cylinder in the airing cupboard in an upstairs bedroom. I
have a control panel that sets when the h/w and c/h comes on. I have a
grundfos selectric 15/50 pump, also in the airing cupboard. Recently
this pump started making a loud whiring/vibrating noise (a bit like the
noise made by Dr Who's tardis) when the hot water came on at 6:30am
ready for baths etc. The boiler still worked, the h/w and c/h still
worked but this noise was too much to take each morning.

I turned the pump up to 3 (was on 1) to see if this would fix it but
made it worse.
I assumed, not being a plumber in any way, that it could be air stuck
in the pipes so I drained one of the upstairs radiators to see if this
would fix the problem.

How did you drain a radiator?

There is probably an airlock tween the boiler and the valves. Vent out
all the gas on each radiator with the radiator key. There maybe a vent
near the valves aswell and also the screw on the side of the pump
needs venting as NP said.

With the original problem I think you need to do a chemical flush. It
fixed my noisy pump and made the radiators warm again!


Needless to say it made it worse!! Now when the
h/w or c/h (or both) come on the boiler starts, the pump starts but
after a few minutes the boiler starts making a noise like it is boiling
which increases and then it cuts out (i assume this is to stop it over
heating much like a kettle).
The pump in the airing cupboard continues to work (i assume as i can
feel it vibrating and changing the speed makes it faster/slower) but
the pipes above and below it don't get hot.

Any suggestions would be very welcome before I call an engineer which
could cost an arm and a leg, and how could I enjoy my nice warm house
with only one arm and one leg?!?