One of our rads gets really hot, even when I turn the thermostat to 0.

[Fluffycloudland77]

Any ideas? it's one in the hall that doesnt even need to be on but it's boiling as soon as the heating goes on.

I suppose the thermostat on it must be broken. We are renting so I cant/wont pay for a new valve.

DH says the stat is probably stuck open which means it would need replacing, sorry. Get onto your landlords.

I think you mean a thermostatic radiator valve.

what make is it? The thermostatic head can be taken off by undoing the knurled ring or large nut (no water leaks out when you do that) so if you can match the make and model, you can often buy a complete new valve for £10-£20 and just swap the head. As this does not require a plumber it might be quicker to do it yourself.

The other thing you can do, at the other end of the rad is a Lockshield Valve. This usually has a plastic cap over the spindle to prevent you fiddling with the adjustment. You can take this cap off and screw the spindle down, using a very small spanner, to restrict water flow. Typically about one turn open from the fully-down position will be enough to keep it modestly warm. If not, adjust is in very small increments of not more than half a turn. If the valve is very old, it might leak from round the spindle. In which case quickly screw it fully closed or fuly open, when it will stop leaking, and ask the LL to get a plumber in.

Our one in the hall is the one that's designed to be on all the time, for some reason - it hasn't got a thermostat though. There is on one the wall in there instead.

So it always gets hotter than the others iyswim.

But if yours has a valve turny thing then I expect it's just broken.

The one in our hall is designed to stay on all the time too, there was a technicalish term the central heating man used when explaining it to me last year when the heating got replaced but I was only half listening!

I've been thinking of turning the other valve down, we have a spanner I can use.

I bought a hot water jacket like you said piglet, I've just got to fit it when dh is out. The airing cupboards so hot at the moment you could bake a loaf in there. Sigh.

claimed

he probably said "bypass"

the rad in the room with the wall stat should have no TRV on it, and the lockshield should be turned down so it heats up slower than all the other rooms, which have TRVs.

Back in the 1970's people used to put the stat in the hall. It is now considered more sensible to have it in the room you use most, provided there is no other source of heat in the room, which will confuse it.

Our hallway one is the one that is designed not to be turned off in our system. It is so that there is always somewhere for the water to be pumped through in the system so that it is ready if you were to turn up one of the other radiators. Otherwise the pump could sieze.

Our thermostat is on the upstairs landing, which is where the boiler is. The problem for us is that there are more radiators to rooms upstairs, but downstairs there are fewer, along with the doors being opened which loses heat. That results in it not really getting warm enough downstairs, or we have to turn the thermostat higher and then the kids are sweltering in their beds in the evening.

My BIL used to say how ace his heating was. Only on 18 degrees and we are in our tee shirts. Yes love, that's because your thermostat is upstairs and you have HUGE radiators downstairs, and have shut all the doors keeping the heat downstairs. It might be 18 on your landing, but it is 25+ downstairs.

Not brilliant. It would be much better if the

..radiators had TRVs on them?

Oh dear I turned it off using pliers.

Is that bad? All the rads have trv's on them.

I can't wait to have our own house and get a luffly new boiler with no immersion tank.

I'm going to put thermal curtain linings back up when I can find them

You need one rad on without a trv. It could also be connected to your hot water tank as an expansion tank. Turn it back on.

What would happen if I don't? They all have trv's on them. The bedroom rad gets hot if the waters on, could that be the expansion rad?

the valve spindle is brass which is a soft metal. Pliers will grind away and deform the brass. You can get a 4-inch adjustable spanner for a few pounds which you can set to fit the flats of the spindle and will not damage it much.

Places like Tesco, Aldi and Wilkinsons sell them. For occasional plumbing work like this you don't need high quality spanners, which can easily cost £20 each.

As Netguru says, you should have at least one radiator permanently open in the room where your wall stat is. However it need not be wide open so you can adjust yours down as long as the rad gets warm. It is very difficult to damage a CH circulating pump as long as it has water in it, and the boiler won't care.

Fluffy, from reading about your old system, which has gravity feed to the cylinder, I know that it will have a feed and expansion tank in the loft.

It does not need an expansion radiator. New, pressurised boilers don't need one either, as they have a pressure vessel inside with a sort of balloon that accomodates expansion.