Radiator Air Valve rounded off so can't bleed, Any ideas on how to do this?

Lady_K

I cannot bleed a radiator that is only 2/3 hot. It always bled fine for 18 years until I had a new boiler and the installer bled the radiator with some pliars as he did not have a radiator key to fit. This was 2 years ago now so can't go back to them. I think it might be the 3/8 one as the rad is quite old and the valve is at the back right top corner. I'm so mad I missed that he had messed up this radiator too as he actually had to replace 2 other radiators at the time that he had done the same thing to.

Anyway is there anything I can do to try and fix it? I've tried pliars and an adjustable spanner with no joy, I also sprayed with wd40 and left it to sit for a while which also hasnt worked. The key just spins around as the valve is just rounded off. Nothing wrong with the radiator even though its old.

Canucklehead

Hi

Do you mean 3/8" vent? Similar to this http://www.buyplumbing.co.uk/VEM-AV14

Older rads had these fitted as a seperate item.

Corgi Guy

Lady_K

It doesnt look exactly like that but similar without the extra end bit on. All I can remember from when its been taken off before is that its like a small nut, it only has the hexagon shape head on and just the other bit that goes in the rad, I measured the head and it is about 3/8". I said 3/8 because I noticed on my other 2 newer rads that they are different, the air release valves are bigger on those and in an easier to get to position even though they are still at the back.

Canucklehead

Hi

These can be replaced ,they unscrew with a small adjustable spanner. Ideally take it out go to a decent plumbers merchant and match it. Refit with PTFE tape.
The only snag is will the rad valves turn off dead tight so you have no water dripping while you are out.

Corgi Guy.

Lady_K

I've already tried an adjustable spanner but I'll give it another go perhaps with a bit more wd40.

When you say rad valves will turning the thermostat to 0 work as I think I'd really struggle loosening anything else as they havent been moved for 20 years now.

The ptfe tape how would I use that and where? I looked it up on google and the pictures look a bit like electrical tape so I'm confused where to use that or is it the stringy stuff thats used to help seal leaks round pipes? If it is it would mean I'd not be able to bleed the rad again after?

Lady_K

Had another go with the adjustable spanner and really struggled because still the nut is totally round and smooth plus the spanner didnt stay in set size position which doesnt help and there is no way to lock it to the size (prob a cheap spanner). Anyway I thought because the nut is totally round and everything just slips on it tight or not I thought I would stick some carpet tape which is really sticky to the flat bits of the spanner thinking it might create some grip and because its spongy I thought once the spanner closed over it the spongy bits would spray out the sides and might stop it from slipping so much. I tried once and felt it grip a tiny bit but then the size slipped again so I stuck carpet tape over the size winder too and then it finally worked.

At the moment I don't know how to empty the rad to replace the air valve but I guess it will have to be done at some stage. I've got a lot of odd bolts in a jar that one probably would fit but its getting it out to measure and replace without getting flooded thats the problem but I think I will sort through them and have some that look like they might fit ready to try quickly next time it needs bleeding.

I also thought afterwards maybe double sided tape could be useful to try if anyone else has the same problem as thats also really sticky on both sides. I did have some of that too but forgot about that till after

I forgot to ask, I did bleed it while the heating was on, its a combination condensing boiler will it be ok to leave it or will this cause any problems? it sounded quite bubbly after the radiator got totally hot to the top does that mean anything?

debbie42

Lady_K wrote: »

I forgot to ask, I did bleed it while the heating was on, its a combination condensing boiler will it be ok to leave it or will this cause any problems? it sounded quite bubbly after the radiator got totally hot to the top does that mean anything?

I'm just about to bleed a radiator, and understood that the heating should be off, not on?

Lady_K

I had read that too but I'm not quite sure if it has an effect or if its just simply because if rads are hot any water that comes out at the end of the bleeding it could be hot on your fingers. Only reason I did leave mine on is because when I got upstairs I had forgot to turn it off so just went ahead. I would usually do it with heating off though.

debbie42

Yes, the hot water could be an issue! I vaguely remember reading somewhere that you can cause more problems with letting air in if the heating is on. but I'm not an expert in any sense of the word and will double check before I do mine.

Mine is a combi (not condensing though) and last time it was bled we had to top up the water in the system. This was for replacing a whole radiator, though. It might be worth checking the pressure after it's bled.

Hopefully someone more knowledgeable than me will confirm, or otherwise!