Stuck Lockshield Valve on radiator

turbo

We had a new boiler in Summer 2018 and the system was power flushed. The radiator in the living room is slightly warm at the top only. No air in radiator. I've checked the TRV and it's not jammed. We have had the radiator for 14 years. The pipe that leads to the lockshield valve is warm. I've tried all types of spanners/pliers but have been unable to open the valve. Access is not good as the lockshield valve end is about three inches from the wall. I've looked at lots of videos that show how to turn the lockshield valve on or off. It's a square spindle on the lockshield valve. It's a 2m long radiator. Is there anything I can do to fix this.?

neilmcl

Try a bit of wd40 down the spindle and leave for a bit before trying again with a pair of adjustables. Remember, it's anti-clockwise to open.

Also, you say you've checked the TRV, have you actually took the TRV head off to see if the pin on the valve is stuck down.

TBH, if the lockshield is seized then generally they're seized in either closed or fully open position and if you getting heat in the rad then it's probably already fully open which would suggest the problem is further back down the line and you need to balance the other rads, starting with the ones upstairs.

turbo

Thank you neilmcl. I did take off the head of the TRV and the pin was moving.
I will do some reading about balancing radiators. My husband has a multimeter. Is that suitable for balancing radiators.? I have tried switching all radiators off apart from the living room one and that did not seem to make much difference. Thanks again for your reply.

EssexExile

turbo wrote: »

Thank you neilmcl. I did take off the head of the TRV and the pin was moving.
I will do some reading about balancing radiators. My husband has a multimeter. Is that suitable for balancing radiators.? I have tried switching all radiators off apart from the living room one and that did not seem to make much difference. Thanks again for your reply.

If it still didn't heat up with all the others turned off then one of the valves is off or there is a blockage.

George333

turbo wrote: »

Thank you neilmcl. I did take off the head of the TRV and the pin was moving.
I will do some reading about balancing radiators. My husband has a multimeter. Is that suitable for balancing radiators.? I have tried switching all radiators off apart from the living room one and that did not seem to make much difference. Thanks again for your reply.

A multimeter won't help, read up on balancing the system or there are some good videos on utube. Plumberparts and skill builder, Roger Bisby or something similar are two good plumbers on there.

Belenus

turbo wrote: »

Thank you neilmcl. I did take off the head of the TRV and the pin was moving...

The pin may well be free with the TRV head removed but the TRV head may be stuck in the closed position.

That has happened a few times with our Myson TRVs.

Leave the head off and see if the radiator warms up.

turbo

Thank you Essex Exile, that is useful information.
Thanks George333 for those plumber video recommendations.
Thank you Belenus. I will try that.

Belenus

Belenus wrote: »

..Leave the head off and see if the radiator warms up.

turbo wrote: »

...Thank you Belenus. I will try that.

If it does prove to be a new head you don't need to change the valve.

Just buy a new matching head or, if not separately available, buy a new TRV unit but just use the new head on the existing valve and keep the new valve for possible future use.

turbo

Hello Belenus, I've taken the head off the TRV and it hasn't made any difference to the lack of heat in the radiator.