leaking radiator valve

coincounter

Yes, apologies for resurrecting such an old thread. It's just that this is the thread I discovered when googling leaking Belmont valves and I thought I would add my tuppenceworth at the end for anyone in future who has had the same problems as me. My offer of posting out new silicone seals is to anyone and not just the original poster.

Now I have replaced the o-rings in my valves I am very pleased with the result as they look and feel very smart. I had the opportunity to replace all the valves in my house with new thermostatic valves as I am getting my boiler replaced soon, but I decided that this would be a waste of the old valves, an unnecessary expense and also the new ones would look out of place. Plus it would take longer to do and there would be a risk of me introducing new leaks! I suspect that a new TRV is likely to fail before my old Belmont valve needs servicing again, and besides, the old valve is far quicker to service than draining the system to replace a new one. The heat in our house has always been well balanced and the single thermostat in the hallway does as good a job as anything, I believe. Also, the old valves look better in my opinion than any new valves I could find in my price range. It would be nice to replace the old grey lockshield caps though, as a few of these are a bit shabby, but I can’t find any anywhere.

rayG3NOD

coincounter wrote: »

Belmont valves are worth repairing as the seals can be repaired/replaced without draining the system down.

• Before starting, loosen the valve by winding the radiator off then on and off again, then leave half on. Wrap an old towel round the valve as it will leak slightly
• Next, you undo the screw on the wheelhead, and lift off the wheelhead.
• Then lift off the thin plate that strengthens the wheelhead connection to the spindle.
• The top lock nut needs taking off – unscrew this in the anticlockwise direction. Clean all the parts as you are taking them off as they will go back on easier.
• Unscrew the spindle in the clockwise direction – you can use the wheelhead to do this. As it comes out it will leak slightly, but should stop (or at least slow down to a tiny dribble) as the spindle lifts out. If it continues to gush, put the spindle back in, screw it up and down a few times and try again.
• Carefully remove the old red o-rings from the spindle using a small screwdriver.
• Clean everything and either put new o-rings on with a bit of silicone/valve grease, or wind 3 turns of PTFE tape round the o-ring grooves and hold in place with the old o-rings.
• Replace the spindle and locknut and wheelhead.

The o-rings are notoriously expensive - ~£1.50 each +P&P. I think they used to be made from butyl, but a modern upgrade would be red silicone. They are Imperial British standard size BS012. These can be bought from RS for ~£6 for 50 +~£5 P&P, but if you just want a few then e-mail me and I can send you some for 50p each plus 50p P&P.

BS012 O-Ring Size Inner diameter x Cross section (mm): 9.25 x 1.78

Hi.

When i first started to use these rings, they cost 1 old penny each, and i lost quite a few rolling around in my tool box.
Now i want some for my sisters heating system and do object strongly to the increases ( since i became a pensioner ). Where do you get them from

Ray G3NOD