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Main boards => The Chat Room => Topic started by: Scrumpy on December 09, 2022, 08:33:33 AM

Title: Bleeding radiator..
Post by: Scrumpy on December 09, 2022, 08:33:33 AM

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..
Title: Re: Bleeding radiator..
Post by: klondike on December 09, 2022, 09:53:30 AM
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.
Title: Re: Bleeding radiator..
Post by: Scrumpy on December 09, 2022, 10:54:58 AM

Oh! dear.. That sounds scary.. but I am going to give it a go.. Thank you..
Title: Re: Bleeding radiator..
Post by: klondike on December 09, 2022, 11:15:31 AM
It's easy enough.

If you've done it before  :grin:

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.

https://www.youtube.com/watch?v=YR97NZdVWbY
Title: Re: Bleeding radiator..
Post by: Diasi on December 09, 2022, 11:23:00 AM
Quote from: Scrumpy on December 09, 2022, 08:33:33 AMMy 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.
Title: Re: Bleeding radiator..
Post by: klondike on December 09, 2022, 12:24:35 PM
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.
Title: Re: Bleeding radiator..
Post by: Alex on December 09, 2022, 01:31:16 PM
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 :shocked:  !  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  :upvote:
Title: Re: Bleeding radiator..
Post by: Scrumpy on December 09, 2022, 03:31:43 PM
Quote from: Alex on December 09, 2022, 01:31:16 PMI didn't know that the screw came out fully - but I do now so be careful Scrumps  :upvote:
Alex.. That is so interesting.. I never knew that..
Quote from: Diasi on December 09, 2022, 11:23:00 AMDoes 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.. 
Title: Re: Bleeding radiator..
Post by: Michael Rolls on December 09, 2022, 04:18:21 PM
Result!
Title: Re: Bleeding radiator..
Post by: Raven on December 09, 2022, 04:44:18 PM
Well done :check: 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.
Title: Re: Bleeding radiator..
Post by: Scrumpy on December 09, 2022, 06:25:48 PM
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..
Title: Re: Bleeding radiator..
Post by: klondike on December 09, 2022, 07:26:24 PM
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.
Title: Re: Bleeding radiator..
Post by: Ashy on December 09, 2022, 07:47:13 PM
If you have a cold bottom, sit on the radiator.
Title: Re: Bleeding radiator..
Post by: Raven on December 09, 2022, 09:22:39 PM
Quote from: Ashy on December 09, 2022, 07:47:13 PMIf you have a cold bottom, sit on the radiator.

 :rofl:
Title: Re: Bleeding radiator..
Post by: klondike on December 09, 2022, 10:12:02 PM
:grin: :grin: :grin: :grin:
Title: Re: Bleeding radiator..
Post by: Diasi on December 09, 2022, 11:04:02 PM
Quote from: Scrumpy on December 09, 2022, 06:25:48 PMI 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..
The heating should be off & the radiators cold, 
a: for safety
b: to let the air pockets settle as they're not being pumped round the system or even air being drawn into the system.

From what you describe there was magnetite sludge in the radiator which has moved elsewhere in the system & may not cause any issues or may block another radiator at some point.
Title: Re: Bleeding radiator..
Post by: Diasi on December 10, 2022, 08:18:27 AM
We're fortunate insomuch as our central heating has plastic piping & runs on a manifold system & not a ring circuit.

The plastic piping virtually eliminates the magnetite sludge & the manifold system ensures that each radiator gets an equal amount of hot water so they all heat up to the same temperature at the same time.
Title: Re: Bleeding radiator..
Post by: Scrumpy on December 10, 2022, 09:12:16 AM
Quote from: Ashy on December 09, 2022, 07:47:13 PMIf you have a cold bottom, sit on the radiator.
:grin: :grin: :grin:


I have listened to all that has been said and will not bleed the radiators when water is hot..   I do have insurance cover and someone is coming out in January..  People with greater problems than mine..