I'm a little stumped with a problem I'm having with our heating.
All the radiators except one gets hot (hot, not just warm). The radiator valve is open, and I've tried various positions of the lockshield valve (from closed to half open to fully open) with no effect. The radiator is an old one (well, not new at least! Same age as the rest of them) and is a very long double one (about 7+ foot long?) - all the rest are much shorter ones. I tried bleeding the radiator and found that it didn't need it. This radiator gets slightly warm (as in doesn't feel cold - but it doesn't feel remotely warm if you see what I mean).
I've tried turning the pump up from 1 to 3 and it did make it marginally slightly warmer, but still nothing high enough to warm the room - I'd still call it cold.
The radiator inlet (with the adjustable valve) is hot (hot as the rest of the radiators around the house) but the radiator side of the valve doesn't feel any hotter than it might be through conduction of heat from the pipe. The radiator outlet (with the lockshield) is cold (or as cold as the radiator).
The possibilities I've thought of are these:
1.) Radiator valve is blocked/stuck - the valve feels like its opening normally (it screws up and down) but something is stopping the water flowing into the radiator. This fits in with the inlet pipe being hot, but the radiator just past the valve not being hot. 2.) Radiator is full of sludge - though I'm not sure about this as it would have to be on both front/back parts - which seems strange.Any suggestions?
I'm planning on putting TRVs onto most radiators sometime and I'd like to also flush through the radiators at this point - but I don't want to have to do this immediately.
Thanks
D