Draining a radiator

Caporegime
Joined
18 Oct 2002
Posts
25,287
Location
Lake District
I have a small radiator that I want to drain so that I can add cleaner to my closed loop system. I have closed both valves isolate the radiator. The radiator has a drain off valve on the lock shield side which a radiator bleed key appears to fit on to but when I try to turn it, the key appears a fraction big as it 'skips'.

I can't get pliers on it as it's recessed in a circular section. Any ideas?
 
I removed a radiator few months ago as we were having the spare room re-plastered. I just put a load of old towels down and have a washing up bowl ready underneath one of the valves as it was slowly unscrewed - could work for you?
Or do you have a needle nose pliers?
 
I removed a radiator few months ago as we were having the spare room re-plastered. I just put a load of old towels down and have a washing up bowl ready underneath one of the valves as it was slowly unscrewed - could work for you?
Or do you have a needle nose pliers?

I think this is your best option. Close the valves off each side and disconnect the nut on either side which holds the radiator to the valve. There will be quite a gush of water to start with, I normally start one side and when the water has stopped slowly tip the radiator to one side while you lift it off the wall. If it's a small radiator it will be easy.

Just make sure you take note of Maccy's comment and have loads of towels. They tend to have horrible black sludge inside them which you don't want on your carpet.
 
buy a different bleed key or file the head of the bleed key down so its a bit more square..

If not just undo the valve with it turned off and bleed it into a bowl..
 
takes a few minutes to take a radiator off, easier with two people then you can take one end off , plug the hole with the others guy thumb and a towel quickly undo the other side and straight outside with the radiator.

If doing it by yourself the best way is to get an old ice cream container, cut a slot out of the side near the radioator pipe so you can slide it under the valve and just loosen it so it leaks into the container.
 
Last edited:
When taking the radiator off you can save the hassle of emptying it before removing it from the wall by loosening both ends just enough to allow you to lift the rad off its wall mounts and rotate it down so that it is laying on the floor. From here you can finish loosening off the ends and remove the rad and carry it away upside down to empty outside or in the bath.

Much less hassle then faffing about trying to drain in to containers.
 
So I had another go at this over lunchtime, turns out the valves at either end aren't holding, I slackened off the nut on the valve to the radiator and a fair bit of water came out, undid the bleed at the top expecting no pressure but it squirted out, as I was running out of time, I did everything back up and re-pressurised the system.
 
By taking one radiator off do you need to drain the whole system or just shut the values for that 1 radiator?

Generally just turn the valves at the ends of the rad you want to remove. Currently have 2 off in my house without draining the system.
 
When taking the radiator off you can save the hassle of emptying it before removing it from the wall by loosening both ends just enough to allow you to lift the rad off its wall mounts and rotate it down so that it is laying on the floor. From here you can finish loosening off the ends and remove the rad and carry it away upside down to empty outside or in the bath.

Much less hassle then faffing about trying to drain in to containers.

This...we had a problem with one of our radiators a little while ago and the plumber that sorted it did this. Saved so much time and messing about with bowls etc.

Other option is to drain the radiator into a thick carrier bag. Can be easier to make sure you don't spill too much water trying to drain it into jugs / bowls. Just make sure the bag hasn't got any holes in it first. ;)
 
So I had another go at this over lunchtime, turns out the valves at either end aren't holding, I slackened off the nut on the valve to the radiator and a fair bit of water came out, undid the bleed at the top expecting no pressure but it squirted out, as I was running out of time, I did everything back up and re-pressurised the system.

Are you absolutely sure that you have closed the valves properly?

Seems like a basic question but I would be surprised if the valves are broken as they are generally very basic. If they are broken you will need to drain the system.
 
So I had another go at this over lunchtime, turns out the valves at either end aren't holding, I slackened off the nut on the valve to the radiator and a fair bit of water came out, undid the bleed at the top expecting no pressure but it squirted out, as I was running out of time, I did everything back up and re-pressurised the system.

By the sounds of it, the water you saw coming out was probably from just the rad. Just make sure the valves are closed down in the right direction too!

Then let water into a bowl and open bleed valve at the top of the rad to help force the water out.
 
Generally just turn the valves at the ends of the rad you want to remove. Currently have 2 off in my house without draining the system.

Thanks, I am assuming then, when you are done to just reconnect the radiator and add some water to the system?
 
Are you absolutely sure that you have closed the valves properly?

Seems like a basic question but I would be surprised if the valves are broken as they are generally very basic. If they are broken you will need to drain the system.

I turned the lockshield, clockwise with grips and screwed the other end clockwise, so yes, I'm sure.
 
Back
Top Bottom