What is this valve called?

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davidjpowell

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Now I know never to touch one again. Nasty thing will not seal, but loves spraying me with water
 
It is the pump isolator as Renault says.

I guess it's leaking, judging by the water trail.
 
It is. Part of an ongoing bigger problem with a boiler and heat exchanger.

Sadly touching this valve has upset it and without knowing its name sourcing a replacement is proving difficult.

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Turn the heat right up, it may cause the valve to reseal after a few days as the inhibitor gets into the spindle clearance.
 
Dieselman said:
Turn the heat right up, it may cause the valve to reseal after a few days as the inhibitor gets into the spindle clearance.

Can't do this as the heat exchanger at the other end is not working

Water is bring returned hot and the system ain't liking it very much. I suspect the water is being superheated and turning to steam.
 
What heat exchanger, presumably not the boiler one? The boiler thermostat should regulate the water temperature irrespective of inlet temperature, but how is the hot water returning, there must be a bypass valve operating when it shouldn't.
 
No it supplies water to two heat exchangers, one which heats air as part of an air handling unit,and one that heats a swimming pool water.

There is a three way valve in the heat exchanger that does not seem to be working. A man who knows more is looking at that on Monday.

In the meantime while trying to bleed air, I messed with the screw and am trying to solve that particular issue.

Sadly its also affected the heating in the room where the tree is going, so pressure is on...
 
Christmas trees prefer no heat.. ;) :D

I find 3 way valves to have poor reliability, a pair of single zone valves is a better option.

Can't you manually actuate the 3 way valve to be where you need the water to flow to, it should have an actuator lever.
 
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Dieselman said:
Christmas trees prefer no heat.. ;) :D

SWMBO prefers heat though...

No choice in the three way valve, it's part of what seems to be a complex system.

Tried the manual activation, but it seems to the gate rather than the motor that is seized

Either that or it's jammed by the heat and something else is at fault,
 
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Its a pump union/valve
I would avoid the ball type and go for the old fashioned gate valve type
The ball type are prone to weeping through the spindle. At least with the old gate type, if it does weep, the spindle can be packed with a bit of hemp & paste.

edit
The end that fits to the pump is pretty standard in the uk (I know because I have spent ages trying to find a pair of non-standard ones - probably american)
The end that fits to the pipework will obviously need to be sized to fit - your picture looks like 22mm but worth checking before you buy, could be 28mm.
 
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Its an isolating valve so designed that you can shut off the water flow both ends enabling you to change the pump
 
Now its getting complicated. Plan A was to buy a replacement to swap. Plan B, that I am less keen on is to take it off and make sure I get as direct replacement as I can.
 
Now its getting complicated. Plan A was to buy a replacement to swap. Plan B, that I am less keen on is to take it off and make sure I get as direct replacement as I can.

The second and third one in post 14 are direct replacements.
 
PUMP ISOLATION VALVES a classic catch 22 situation. You fit them so you can isolate the pump to change it without draining the complete system. In service they are open but as soon as you try to employ them=isolate the pump --- they begin to leak thus defeating their primary purpose. This means you end up draining the entire system. Due to the dimensions of the pump flanges and feed/exit pipe clearances you have buy and install new isolation valves when you renew the pump otherwise the pump wont fit. Very cunning trick that. You can buy them in any plumbers merchant -- B and Q even--- Just check the plastic bag is not broken / the fibre washers are present and the pump mating flanges are not damaged. I find its easiest to reassemble the new pump plus the virgin = never been screwed/turned isolation valves on the bench [use some boss white on the flanges/washers] and remake the 22mm compressing couplings with the olives and existing nuts still on the original pipework [ a little PTFE tape round the old olives can help here also] if they are showing their age. MAKE SURE THAT PUMP IS ON THE RIGHT WAY ROUND AND IN THE CORRECT ORIENATATION according to the enclosed instructions with the new one. Wilo or Grundfoss are fine.
 

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