Hi there,

I've got a problem with my feed and expansion tank - when I bled the radiators last weekend, the overflow from the feed and expansion tank in the loft started leaking. I turned down the water pressure at the main stop cock (that helped a bit) but since then it keeps leaking whenever the central heating's on.

Wasting water, leading to damp + I'm worried about it getting worse. The feed and expansion tank's in the loft, covered in cobwebs...so if there's a way to fix it by adjusting the central heating, water pressures, turning off some radiators, then I'm all for it. Radiators working well, not leaking, though there are banging noises from the pipework sometimes (not very often). The thermostat on the boiler is set at 60 degrees - maybe it's broken and keeps boiling the pipework?

So over to you - grateful for your help - I'm not the best at DIY so please keep it simple!!

Angelic88

angelic88 wrote:
Hi there,

I've got a problem with my feed and expansion tank - when I bled the
radiators last weekend, the overflow from the feed and expansion tank
in the loft started leaking. I turned down the water pressure at the
main stop cock (that helped a bit) but since then it keeps leaking
whenever the central heating's on.

Wasting water, leading to damp + I'm worried about it getting worse.
The feed and expansion tank's in the loft, covered in cobwebs...so if
there's a way to fix it by adjusting the central heating, water
pressures, turning off some radiators, then I'm all for it. Radiators
working well, not leaking, though there are banging noises from the
pipework sometimes (not very often). The thermostat on the boiler is
set at 60 degrees - maybe it's broken and keeps boiling the pipework?

So over to you - grateful for your help - I'm not the best at DIY so
please keep it simple!!

Angelic88




Sounds like you've lost the air pocket at the top of the expansion tank
which changes volume to accomodate the expansion of water when it's
heated. Some tanks have a rubber diapraghm in them separating the air
from the water to prevent the air from getting away, and some don't.

Look for something on that tank which looks just like a tire filling
valve and use a bicycle pump to squirt some air into it. Somewhere
around ten full strokes ought to be enought.

If you don't find that "tire valve", then you'll have to shut the
heating system down, close the water supply valve to the system and
drain the water out of the expansion tank, probably having to open a
bleed valve at the top to let air in while the water drains out. You
might have to seek seek a more knowledgable assistant to help you with that.

HTH,

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.