A bit of a long description but I think it's all relevant so please bear with me.
We live in a flat; out hot water comes from a hot water tank and our
cold water comes from the mains. The hot water is pumped to the whole
flat by a NewTeam Varispeed SI pump which is a replacement one fitted
18 months ago. The original one just seemed to have died electrically
and was installed when the bathroom was refitted 5 years ago.
Earlier this year, I noticed the overflow from the cold water tank
above the hot water tank (is there a technical name for this?) was
emitting water. I diagnosed this as being a backflow of cold water
from the shower mixer along the hot water supply to the shower and then
into the hot water tank. To fix this I got a plumber in who fitted a
non-return valve between the hot water tank and the pump. I suppose
ideally it should have been inserted into the hot water pipe closer
to the shower but there wasn't really a convenient run of accessible
pipework to do this. Anyway, the problem was fixed but of course
there is still some cold water pressure going back through the pump
because of the location of the non-return valve.
However, our pump has now started to leak from somewhere within the pump
(i.e. not at either of the connections). It doesn't seem to leak when
the pump is in use but will usually do so when we haven't used any hot
water for some time. The leak can be stopped by turning off the hot
water supply to the pump and opening a hot water tap somewhere else
in the flat (we also turn off the electricity supply to the pump but
this is not critical). At this point there will be a small but steady
drip of cold water coming from the open hot water tap which is coming
from our original backflow problem - turning off the hot water tap will
eventually result in a leak from the pump.
Questions:-
Could the backflow pressure through the pump have damaged it to have
caused the leak? I know this pump is a "cheap and cheerful" one but the
installation instructions for a new Salamander one, which our plumber
was going to fit recently, specifically said that there should be no
non-return valves either side of the pump, so can I repair the pump or
just replace it with an identical model? The only thing that I can see
that might have failed within the pump is the inlet plate O-ring.
It seems to me that the true source of the problem is the shower mixer
so is there a better way of curing the backflow problem? Should there
be non-return valves in the shower mixer? If there are, could they have
become damaged or gone faulty and can they be replaced? Will replacing
the shower mixer help? The shower make is currently unidentified.
We live in a flat; out hot water comes from a hot water tank and our
cold water comes from the mains. The hot water is pumped to the whole
flat by a NewTeam Varispeed SI pump which is a replacement one fitted
18 months ago. The original one just seemed to have died electrically
and was installed when the bathroom was refitted 5 years ago.
Earlier this year, I noticed the overflow from the cold water tank
above the hot water tank (is there a technical name for this?) was
emitting water. I diagnosed this as being a backflow of cold water
from the shower mixer along the hot water supply to the shower and then
into the hot water tank. To fix this I got a plumber in who fitted a
non-return valve between the hot water tank and the pump. I suppose
ideally it should have been inserted into the hot water pipe closer
to the shower but there wasn't really a convenient run of accessible
pipework to do this. Anyway, the problem was fixed but of course
there is still some cold water pressure going back through the pump
because of the location of the non-return valve.
However, our pump has now started to leak from somewhere within the pump
(i.e. not at either of the connections). It doesn't seem to leak when
the pump is in use but will usually do so when we haven't used any hot
water for some time. The leak can be stopped by turning off the hot
water supply to the pump and opening a hot water tap somewhere else
in the flat (we also turn off the electricity supply to the pump but
this is not critical). At this point there will be a small but steady
drip of cold water coming from the open hot water tap which is coming
from our original backflow problem - turning off the hot water tap will
eventually result in a leak from the pump.
Questions:-
Could the backflow pressure through the pump have damaged it to have
caused the leak? I know this pump is a "cheap and cheerful" one but the
installation instructions for a new Salamander one, which our plumber
was going to fit recently, specifically said that there should be no
non-return valves either side of the pump, so can I repair the pump or
just replace it with an identical model? The only thing that I can see
that might have failed within the pump is the inlet plate O-ring.
It seems to me that the true source of the problem is the shower mixer
so is there a better way of curing the backflow problem? Should there
be non-return valves in the shower mixer? If there are, could they have
become damaged or gone faulty and can they be replaced? Will replacing
the shower mixer help? The shower make is currently unidentified.
