Hi,

My CH pump is easily accessible and has isolating valves above and
below. The isolating valves turn easily with mole grips and I believe
I shut them off by turning them clockwise and seeing the spindle go
into the body of the valve. I undid with a wrench the large nuts
holding the pump in place - they undid easily. I had put down plenty
of old curtains and cloth around the pump and I wiggled the pump
slightly. Water started come out round the seals on the pump inlet and
outlet. I let the water run around the seal for a minute (maybe it was
only 30 seconds) and then I lost my nerve and refitted the nuts. I'm
really concerned that if I remove the pump and I haven't actually
closed the isolating valves that I will get a deluge of water that I
can't stop. How long should I expect the water to flow out of the pump
so that it empties and I can feel confident the system is actually
sealed?

The pump is in an upstairs room so I have visions of flooding the room
below and bringing the ceiling down.

Separately, if other valves on the system with "old style" tap heads
or "gate valves" are seized (yes, that old one !) what is the risk of
the valve "falling apart" if I try to free them using some kind of
wrench? Is there some "miracle" penetrating oil that will help free
the valves or is it best to drain down and have them replaced - then
use them every six months to stop them seizing?


Thanks

Clive

Clive formulated the question :
Hi,

My CH pump is easily accessible and has isolating valves above and
below. The isolating valves turn easily with mole grips and I believe
I shut them off by turning them clockwise and seeing the spindle go
into the body of the valve. I undid with a wrench the large nuts
holding the pump in place - they undid easily. I had put down plenty
of old curtains and cloth around the pump and I wiggled the pump
slightly. Water started come out round the seals on the pump inlet and
outlet. I let the water run around the seal for a minute (maybe it was
only 30 seconds) and then I lost my nerve and refitted the nuts.

Expect about a litre to come out, but keep in mind these are gate
valves which never fully seal the flow. Clock-wise looking at the valve
from the spindle is off and the spindle should also wind into the body.

If the valves turn so far, then stop fairly solidly, that is a good
sign that the valve is tight shut. You might lay some plastic sheet
down to catch most of it, with something suitably absorbent on top.

Undoing the top nut only and allowing that to drain first, means you
can get a better idea of how much water is passing the two valves. That
way you are dealing with less initial bulk of water escaping.

Don't over tighten the valves with the mole grip - they are only
intended to be closed with a small hand wheel and could be damaged.


--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

"Clive" wrote in message
...
Hi,

My CH pump is easily accessible and has isolating valves above and
below. The isolating valves turn easily with mole grips and I believe
I shut them off by turning them clockwise and seeing the spindle go
into the body of the valve. I undid with a wrench the large nuts
holding the pump in place - they undid easily. I had put down plenty
of old curtains and cloth around the pump and I wiggled the pump
slightly. Water started come out round the seals on the pump inlet and
outlet. I let the water run around the seal for a minute (maybe it was
only 30 seconds) and then I lost my nerve and refitted the nuts. I'm
really concerned that if I remove the pump and I haven't actually
closed the isolating valves that I will get a deluge of water that I
can't stop. How long should I expect the water to flow out of the pump
so that it empties and I can feel confident the system is actually
sealed?

The pump is in an upstairs room so I have visions of flooding the room
below and bringing the ceiling down.

Separately, if other valves on the system with "old style" tap heads
or "gate valves" are seized (yes, that old one !) what is the risk of
the valve "falling apart" if I try to free them using some kind of
wrench? Is there some "miracle" penetrating oil that will help free
the valves or is it best to drain down and have them replaced - then
use them every six months to stop them seizing?


Thanks

Clive

When I tried to replace my CH pump, I found that the 20-year-old gate valves
did very little isolating at all, with large quantities of water flowing
through them even when "closed". In the end, I had to drain the system. I
replaced the gate valves with ball valves, which are supposed to perform
better.

"Simon" wrote in message
...
"Clive" wrote in message
...
Hi,

My CH pump is easily accessible and has isolating valves above and
below. The isolating valves turn easily with mole grips and I believe
I shut them off by turning them clockwise and seeing the spindle go
into the body of the valve. I undid with a wrench the large nuts
holding the pump in place - they undid easily. I had put down plenty
of old curtains and cloth around the pump and I wiggled the pump
slightly. Water started come out round the seals on the pump inlet and
outlet. I let the water run around the seal for a minute (maybe it was
only 30 seconds) and then I lost my nerve and refitted the nuts. I'm
really concerned that if I remove the pump and I haven't actually
closed the isolating valves that I will get a deluge of water that I
can't stop. How long should I expect the water to flow out of the pump
so that it empties and I can feel confident the system is actually
sealed?

The pump is in an upstairs room so I have visions of flooding the room
below and bringing the ceiling down.

Separately, if other valves on the system with "old style" tap heads
or "gate valves" are seized (yes, that old one !) what is the risk of
the valve "falling apart" if I try to free them using some kind of
wrench? Is there some "miracle" penetrating oil that will help free
the valves or is it best to drain down and have them replaced - then
use them every six months to stop them seizing?


Thanks

Clive

When I tried to replace my CH pump, I found that the 20-year-old gate
valves
did very little isolating at all, with large quantities of water flowing
through them even when "closed". In the end, I had to drain the system. I
replaced the gate valves with ball valves, which are supposed to perform
better.



In this case he can turn all the upstairs radiators off and part drain the
system to the level of the pump. Sounds a far easier afair.

On Sat, 18 Oct 2008 12:47:40 +0100
"Simon" wrote:


When I tried to replace my CH pump, I found that the 20-year-old gate valves
did very little isolating at all, with large quantities of water flowing
through them even when "closed". In the end, I had to drain the system. I
replaced the gate valves with ball valves, which are supposed to perform
better.



Close and open all valves, gate or ball, throughout the system once
every six months or so. That way you dislodge any scale, and other muck,
before it gets too thick.

Ball valves can be sealed open with scale. And gate valves can have
their gates filled with almost anything - then they jam.

R.

In article
,
Clive wrote:
My CH pump is easily accessible and has isolating valves above and
below. The isolating valves turn easily with mole grips and I believe
I shut them off by turning them clockwise and seeing the spindle go
into the body of the valve. I undid with a wrench the large nuts
holding the pump in place - they undid easily. I had put down plenty
of old curtains and cloth around the pump and I wiggled the pump
slightly. Water started come out round the seals on the pump inlet and
outlet. I let the water run around the seal for a minute (maybe it was
only 30 seconds) and then I lost my nerve and refitted the nuts. I'm
really concerned that if I remove the pump and I haven't actually
closed the isolating valves that I will get a deluge of water that I
can't stop. How long should I expect the water to flow out of the pump
so that it empties and I can feel confident the system is actually
sealed?

Fact of life with gate valves in a hard water area - the seats get clagged
up and no longer shut off the flow fully.

Best to drain down the system - the inhibitor could probably do with a
change anyway.

--
*I'm out of my mind, but feel free to leave a message.

Dave Plowman London SW
To e-mail, change noise into sound.