Radiator not working - TRV?

[TheOwenses]

Can anyone help please? We have 5 radiators upstairs, 2 of which are fitted with TRV's and 3 fitted with 'normal' on/off valves. As it tends to be a lot warmer upstairs than downstairs generally, we have had all of these radiators turned off for the last four or five months. However, due to the recent bad weather, we have just turned them all back on to find that one of them is not working.

The radiator in question is fitted with a TRV which has a setting of 0 to 6. We've taken the valve off and ensured that it twists freely and that the pin mechanism is working. However, we've also noticed that even when the heating is on throughout the house, the pipes leading in to the radiator itself are both stone cold so I'm not sure whether this means it is less likely to be a problem with the valve and more likely to be something else entirely?

We'd be grateful for any ideas anyone can put our way! We currently have two toddlers in the room so would like to sort it ASAP as it's a little chilly at night now.

 

[AWheating]

Is the other valve on the other side fully open? Does wata come out the vent? Try running the heating with all the other radiators bar this one turned off to see if its a bit of air.

 

[andyplumber2009]

the pipes will be cold because no water is flowing, so could still be the valve. TRV's although 0 to 6 do not shut off completely and to shut them off to change a rad you need a little cap to compress the pin to a closed position.

 

[diamondgas]

When you know how you get the knack for 'tapping' in the right place to shake free a stuck valve. However that can cost you quite a bit that "know how"!

When you remove the valve head does the pin in the valve move in and out when de-pressed? If it doesn't that usually indicates a seized valve. If it does then issues could lie elsewhere.

 

[Clint 1979]

Sounds like the TRV is ok from what you have said. Bleed the rad to make sure there is no air inside, as said earlier shut off all rad valves and stats except the one that is not heating up (open the valves on this one) and turn the heating on......if the rad heats up then call a plumber to balance the system for you.
if it doesn't heat up then call a plumber anyway to have a look for you....could be TRV sticking in the valve, lock shield stuck, air in the system, sludge/blockage in the pipes, or something else that a plumber should be able to find for you.
If its a sealed system, make sure all rads are bled and system is pressurised.

good luck

 

[Sparkgap]

When you know how you get the knack for 'tapping' in the right place to shake free a stuck valve. However that can cost you quite a bit that "know how"!

When you remove the valve head does the pin in the valve move in and out when de-pressed? If it doesn't that usually indicates a seized valve. If it does then issues could lie elsewhere.

Used to have a lot of problems with the old Drayton TRVs, they'd shut down over summer when weather was warm and would stick shut. Usually taking the head off and jigling the pin would work but sometimes meant taking the valve off and pushing up the seat.

 

[Centralheatking]

Take the TRV valve head off - ie unscrew it usually anti clockwise

This will expose a small vertical pin - get a nice small tacking hammer
or ball peen hammer and give it a sharp wack this should free it off
turn heating on get full heat to rad. Then turn TRV on to full and screw back on and re-set
to desired setting. Simples CHK

 

[diamondgas]

Used to have a lot of problems with the old Drayton TRVs, they'd shut down over summer when weather was warm and would stick shut. Usually taking the head off and jigling the pin would work but sometimes meant taking the valve off and pushing up the seat.

Just did a couple of sticking Drayton's come in yesterday ... I find that the one's set low tend to stick coz they've, in effect, been off all summer!