westherm rad valve

[teslaman]

please could someone tell me how to remove the head on my westherm trv valve and can I leave it off so rad works manually ?.

 

[D_Hailsham]

please could someone tell me how to remove the head on my westherm trv valve and can I leave it off so rad works manually ?.

Can't give specific info, but there are three methods you can try.

1. There may be a large knurled nut holding the head onto the body. This will unscrew anticlockwise, looking down on the TRV.
2. There may be a screw holding the head in place.
3. There may be a collar holding the head in place. This will move up or down to release the head.

Always set the TRV to the highest setting when removing or replacing.

Why do you want to remove the head? Setting it to the highest setting will achieve the same thing.

Is you rad not heating up? This could be due to a stuck pin. Remove head and you will see the pin sticking out of the body. Try pressing down on the pin with something and then let go. The pin should depress and then spring up. If it won't move it's stuck. Try tapping the side of the valve with a hammer, this might release it. Alternatively use a pair of pliers to try moving the pin. Make sure you don't bend it or pull it right out. (Compare with another working TRV to see how far it moves). A light application of WD40 or a silicon lubricant may help.

 

[teslaman]

thanks for your help, I was being a bit thick as it is obvious how the top comes off.
I took the top off and had to pull the pin up with pliers, the pin now moves up and down, but only if I pull or push it (no springing), the radiator still won't work, I have bled it and there is no air in it and all other radiators are working, could the mechanism in the trv valve be jammed shut ?,
please help ?.

 

[D_Hailsham]

I took the top off and had to pull the pin up with pliers, the pin now moves up and down, but only if I pull or push it (no springing), the radiator still won't work, I have bled it and there is no air in it and all other radiators are working, could the mechanism in the trv valve be jammed shut ?,

Obviously jammed shut. Have you tried tapping the valve with a hammer? Thus might free the stuck bit. If that fails, it's a new TRV. I suggest you get a better quality one - Danfoss, Drayton or Honeywell.

 

[teslaman]

have tried tapping with hammer as you suggested but no luck, looks like I will need to drain system and renew it, oh well it could probably do with some new inhibitor in the system, how much inhibitor would i need ?,
thanks for all your help

 

[D_Hailsham]

looks like I will need to drain system and renew it,

If you have an open vented system (small tank in loft), you can use "bungs" in the feed and vent pipes to set up a vacuum in the system. You then do not have to drain down. B&Q etc sell them; it's called a Draineasy Kit.

how much inhibitor would i need ?

It's usually about 1 can for 10 rads. But it does not matter if you put in too much. You can mix brands.

If you live in a hard water area it's a good idea to add a limescale controller as well, e.g Sentinel X200.

 

[teslaman]

my system has a combi boiler so is a sealed system ?.
as I have a wall thermostat I will probably change the valves for manual ones as I have them on full all the time anyway.

the area is a hard water area, so I will get some x200 as you suggest,

thanks a lot for all your help.

 

[D_Hailsham]

my system has a combi boiler so is a sealed system ?.

In that case, you just release the pressure until it is down to 0. Shut off lockshield valve (count turns to close).
Make sure filling valves are closed.

You should then be able to remove old valve without any water loss

I will probably change the valves for manual ones as I have them on full all the time anyway.

Do you have TRVs on full because (a) you like the rooms to be very hot, or (b) they do not seem to have any effect?

(a) is a personal preference
(b) is because the radiators have not been properly balanced.

See How to Balance a CH System

 

[teslaman]

sorry to be dense again but where is locksheild valve and how do you release the pressure without draining system ?.

the reason I have valves open fully is because the house is a 1930's one and has hardly any insulation, when the weather is milder I let the wall thermostat control the temperature.

thanks again.

 

[teslaman]

will water still leak out from radiator when changing valve ?, as it will still be full?

 

[D_Hailsham]

sorry to be dense again but where is locksheild valve and how do you release the pressure without draining system ?.

The lockshield valve is the one at the other end of the radiator. It will have a plastic cover, which is either a push fit or held on by a screw. Remove this cover and you will set the valve spindle with two flats. Close this valve down with a pair of pliers (turn clockwise looking down - count how many turns)

To release pressure:

Shut of the valves at the boiler
Open the bleed screw in the radiator and let water out until it stops running. This sets up a vacuum on the system. The pressure should drop to 0
Shut the bleed screw - this is important.

Change thermostatic valve

Reset LSV to original position
Open boiler valves and re-pressurise
Bleed rad and check pressure

the reason I have valves open fully is because the house is a 1930's one and has hardly any insulation, when the weather is milder I let the wall thermostat control the temperature.

Did you know there are plenty of schemes to provide cheap or free insulation?

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