some radiators are cold

WIZE

hi all


i have all the radiators on but some are cold

thinking there was an airlock i bled them but all the coming out is cold water.

what would be wrong. i took 2ltr out of one but its still cold the rest are really hot.

Stove Fan

Hi

A few questions

Are the affected rads upstairs or downstairs?

Is the system open vented. ie 2 tanks in loft 1 small ?

Any zone valves fitted on this circuit to the affected rads?

The rads affected are they fitted with thermostatic radiator valves? If so unscrew the head with your hand and push down the pin in several times. Leave the head off. Does the rad heat up? If so refit head. If it now does not warm up replace faulty head.

Are these old radiators and the others are new/newer?

How old is the heating system?

Stove Fan:)

indie armada

check the pressure on the system, should be a gauge in or around the burner. like stove fan says need a bit more info for the lads to be able to help. the only reason i say check the pressure is it was lack of pressure in a system i sorted recently that had same symtoms as you. i introduced water into the system with the heating on and with the colder of the valves closed on each rad. then opened the valves a 1/4 turn at a time and watched the pressure and added more to the system as they began to heat up and the pressure stabilised.

Buford T Justice

If a couple of rads aren't heating correctly, then you most likley have an issue with sludge and silt.

Sparkpea

could be the water pump if they are last on the line, how old is the pump?

JuliusCaesar

I have the same problem. It's the radiator right next to the boiler which is on the landing, next to the immersion. Radiators upstairs and everywhere else in the house are all working, just this one isn't. And I tried bleeding it, in case it was an airlock, but clear cold water ran out, no air at all.

There's only one tank in the attic.

The radiator is old, and completely cold. There's no warmth anywhere in it.

Sparkpea

JuliusCaesar wrote: »

I have the same problem. It's the radiator right next to the boiler which is on the landing, next to the immersion. Radiators upstairs and everywhere else in the house are all working, just this one isn't. And I tried bleeding it, in case it was an airlock, but clear cold water ran out, no air at all.

There's only one tank in the attic.

The radiator is old, and completely cold. There's no warmth anywhere in it.

is there a trv on it? screw the head off

JuliusCaesar

What's a trv?

Sparkpea

thermostatic radiator valve

JuliusCaesar

Thanks, Sparkpea. No, there's no trv on it. Just the on/off knob at one end and an unturnable one on the other end of the radiator. Actually, it occurs to me that the one in my bedroom is only faintly warm, while the rest belt out heat. The newer ones belt out a lot more heat, so I think it may be time to get rid of the old flat panel ones. But in the meantime, any suggestions are welcome. Could it be sludge? And how would I know?

DoneDL

Could just be a case of balancing the system, turn of the hot rads and see if the others heat. It may be sludge in the system and once you get the system moving it may fix the problem, if this doesn`t work then look at pump speed and boiler stat.