One side of radiator is hot the other is not

[FrancisJames]

One side of radiator is hot the other is not.

Its a long radiator a(say about 1.4m) and its the furtherest from boiler on top floor, though there is another radiator on the top floor nearby which is fine.

One side is hot, the left side, but as you move along the radiator, there is less and less heat coming out.

Is this simply a case of bleeding the radiator or something else.

I haven\\\'t got a radiator key at home and it would save me a fruitless journey if it is likely to be a different problem!

Grateful for any help!

 

[simon_d]

if it was hot at bottom and cold at top then it would most likely be air, but for one side to be hot and the other colder, sounds like something in it stopping flow. sounds like your system has sludge and could do with a clean

 

[tabs]

Which side is your trv at and is bi-directional?

 

[FrancisJames]

thanks for advice so far. I'm not sure if it will be sludge as the boiler and pipework for the house were put in in last two years and the radiator i'm having a problem with only put in in the last couple of months as part of a loft conversion - including another radiator that is working fine. Can sludge build up quickly?

The trv is on the side that is cold. Don't know whether it is bi-directional.

thanks again for replies so far

 

[nuts]

Take the head off the trv and keep the spindle pressed down, if the rad warms all over the head maybe broken or it may have been incorrectly seated on the valve. I would turn off the other rads while you try this and if its sludge it may disperse it. You will be better off flushing the system as well.

 

[Slugbabydotcom]

If the rad is not level then it may not be possible to get all the air out.
Should this be the case it may be possible to lift the bleed valve end of the rad if there is enough play in the pipework.
Do not bleed the rad while the system is turned on.

 

[amiablestray]

it's possibly pretty simple

it seems there are two points you can bleed the rad - one little (square - and about 5 mil on mine) and the other is a larger one (of order of a couple of centimeters and hexagonal) which is part of the radiator itself and on mine situated at the top at one end.

I've just fixed mine which had the same problem, and it was the larger hexagonal one that needed bleeding, not the little square one.

I'm guessing the little square one bleeds air from the pipe leading upto the rad, and the the big hex one bleeds air out of the rad itself, however, I'm not a plumber - that's just what I did to fix mine

hope that helps, and that anyone more qualified will say if I've got anything wrong.

 

[TicklyT]

......it seems there are two points you can bleed the rad....
....I'm guessing the little square one bleeds air from the pipe leading upto the rad, and the the big hex one bleeds air out of the rad itself....

Actually, both the bleed valve and the blanking plug vent the same space at the top of the radiator.

If the radiator isn't installed level, and the bleed valve is at the 'low' end, it can leave an air bubble at the high end that will stop water flowing the full length of the header. Either the radiator needs levelling, or the bleed valve and blanking plug need swapping so the bleed valve is at the highest end.

 

[amiablestray]

Actually, both the bleed valve and the blanking plug vent the same space at the top of the radiator.

If the radiator isn't installed level, and the bleed valve is at the 'low' end, it can leave an air bubble at the high end that will stop water flowing the full length of the header. Either the radiator needs levelling, or the bleed valve and blanking plug need swapping so the bleed valve is at the highest end.

Thanks for that - useful to know the proper names for these things.

just to make it clear for other folks like me who don't know what we're talking about - bleeding from the blanking valve (big hex one) definitely had an effect on mine, when bleeding from the bleed valve (little square one) didn't.

I didn't have to level my rad, or swap anything around - all I had to do was bleed the rad from the blanking valve and that fixed it.

From what TicklyT is saying, I'm guessing in a perfect world, it _should fix it when you use the little bleed valve, but where it doesn't, bleeding from the blanking valve might help.