My combi is upstairs and is an open vented installation. Recently the
expansion tank has been overflowing (through the warning pipe) .
I think it is due to the fact that when the water expands it obviously fills
the tank - when it contracts it allows more water in. Then the next time the
heating goes on it expands and overflows.
The tank is very small and I think this is the problem. However, space is a
bit limited due to all the cross timbers. Are there any other solutions - I
am even thinking of converting it to a closed system (it is a Worcester
Heatslave) but I am a bit reluctant in case the 12 year old systems starts
to leak if the pressure is higher. I guess I would have to plumb in a
pressure release vent pipe to the outside wall.
But it would have always done that expansion/contraction thing so
would have always overflowed. You say this a recent...
Sure it's not just the ball valve sticking due to a build up of scale,
a slow leak due to grit or a failing washer?
I take it that you don't have a hotwater cylinder as you state "combi"
another good cause of an overflowing expansion tank is a leak in the
coil in the cylinder. The level of water in the CW storage tank is
normally higher than that in the expansion tank, water always tries to
find a level.
Dave. pam is missing e-mail
Thanks - I did replace the ball valve diaphragm on Sunday. I reckon that I
need to have the tank almost empty to allow for the expansion that takes
place. I will monitor it over the next few days.
I don't have a tank.
"Dave Liquorice" < firstname.lastname@example.org> wrote in message
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