Bleeding radiator..

[Scrumpy]

My living room radiator is not, fully, heating up .. I have tried bleeding to no avail..
I am covered for problems like this .. It is not an emergency as I have heating for the rest if the house..  They will be out in January..
 It is an old radiator so perhaps she is on her last legs..  Bugger..

[klondike]

That doesn't make any sense.

If it isn't fully heating then the only reason I can figure is that it has air in the top so needs bleeding.
The only way bleeding can fail on a ground floor radiator is if there is crap in the bleed valve. Can you hear any air esacape when you open it? If not then you need to clean out the bleed valve.

To do that without getting a flood turn off the taps at each end.
You'll need to use either a spare cap from the end that you can adjust or maybe pliers to do the "balance" end. Note carefully how many turns that takes as it needs resetting to that after you have done to avoid messing up the balance (rate of flow for that rad in relation to others).

With the rad valves closed at each end of the rad take the bleed screw out completely. Use a paper clip or similar to rootle out any crud. Put it back in when done.

Reopen the valves - do the balance one the number of turns it was before and the other fullly open.
Retry bleeding it. You should hear the air and then get water coming out. I always hold a dishrag over it when doing this job to save on mess.

[Scrumpy]

Oh! dear.. That sounds scary.. but I am going to give it a go.. Thank you..

[klondike]

It's easy enough.

If you've done it before 

This Youtube says pretty much what I did apart from noting the number of turns of the balance valve. It does suggest opening one valve to flush the bleed valve out which sounds good to me.

[Diasi]

My living room radiator is not, fully, heating up .. I have tried bleeding to no avail..
I am covered for problems like this .. It is not an emergency as I have heating for the rest if the house..  They will be out in January..
 It is an old radiator so perhaps she is on her last legs..  Bugger..

Does it
a: heat up hot at the bottom but not the top
b: heat up hot at the top but not the bottom
c: heat up equally top & bottom but only gets warm.

[klondike]

That's a possibility I hadn't considered. 

From the wording and mention of bleeding I'd assumed "not fully heating up" meant the top of the rad was cold. I can't think of anything that would leave the top hot and bottom cold but if it is just the rad isn't as hot as the rest with the main valve fully open it may be out of balance or full of crud.

Out of balance just involves opening the balancing valve a tad. Full of crud means flushing out the system which for somebody who hasn't done that before probably means calling somebody out to do it.

[Alex]

A couple of years ago I tried to bleed tha radiator in my utility room only I must have turned it too far and water shot out everywhere.  I was stool with a bucket under the radiator not knowing what to do   !  If I put the bucket down the floor would be flooded, in the end I had no alternative but to put the bucket down and run next door for my neighbour.  He came straight away but the floor was flooded, he spotted a little nut thing on the flood, picked that up and stuck it back in the end of the radiator and the flow of water stopped.

I didn't know that the screw came out fully - but I do now so be careful Scrumps 

[Scrumpy]

I didn't know that the screw came out fully - but I do now so be careful Scrumps 

Alex.. That is so interesting.. I never knew that..

Does it
a: heat up hot at the bottom but not the top
b: heat up hot at the top but not the bottom
c: heat up equally top & bottom but only gets warm.

Diasi.. The top was hot.. 

December 09, 2022, 03:38:46 PM

I very carefully turned the  (screw).. 
some water came out.. I fiddled with the key.. turned it a bit more and it started ' hissing'... More water and more (hissing)..

Gradually the bottom of the radiator started to function properly.. I now have a hot radiator..
I am well chuffed that I have done it when the guy next door couldn't..

Thank you for your help.. 

[Michael Rolls]

Result!

[Raven]

Well done I have to do my ones in Perth sometimes. I take a cloth to hold under the screwdriver, it catches any water that comes out.

[Scrumpy]

I too held a cloth under the screw.. I did it while the heating was on.. .. I knew it was working because the water hissing out was starting  to get hot..
 I was told once that the heating should be  'off' when bleeding a radiator.. I guess for safety reasons..

[klondike]

Don't get too pleased. Hot top cold bottom is apparently a build up of sludge and I think that means your system needs flushing out.

https://idealheating.com/tips-and-advice/radiator-cold-at-the-bottom-possible-causes-and-solutions#:~:text=If%20your%20radiators%20are%20cold,it%20cold%20at%20the%20bottom.

I've never had that but that's probably because I've always made sure that my CH system has an inhibitor in it. My current one has plastic pipes not copper so I don't think it is needed. The sludge comes from an electrolytic reaction between the copper pipes and steel rads.

[Ashy]

If you have a cold bottom, sit on the radiator.

[Raven]

If you have a cold bottom, sit on the radiator.

 

[klondike]