Lukewarn Radiators

[chard]

I have 2 radiators in the upstairs bathrooms of my house which run in conjunction with the hot water, but not the central heating. Both of them now only get warm at the bottom couple of inches. I have tried bleeding them, but nothing has changed.
In addition I have the same problem with one upstairs radiator and one downstairs, which run off the central heating. Again I have bled them, with only a minor improvement.

Can anyone help?? :

 

[corgiman]

when you say bled them did you wait until water came out??

 

[chard]

no, but I left them for 2 hours without the stopper in. It hissed for the first 5 seconds, then nothing - the hot water did not seem to be rising inside. Any ideas? Cheers Chard

 

[corgiman]

sounds like either a blocked cold feed or empty feed and expansion tank

have a look at thre little tank in the loft and see if its full let me know

 

[chard]

Thanks for your reply. I've had a look at the little tank, and it is full, but the water looks very stagnent. Any help/ideas, plus how to fix the problem would be most appreciated.

 

[MANDATE]

I would think if the bottom of the radiators got warm, the problem must be sludge or air in them. If you got neither air or water out when you bled them it suggests sludge to me, or a blocked bleed valve.
You could close off the valves and remove the bleed valves for examination or remove the radiators for flushing.

 

[oilman]

I agree with corgiman, and since your tank is full, it's probably the feed pipe. These usually get blocked just above where the feed pipe joins the rest of the system BUT NOT ALWAYS.

You may have some pipe cutting to do as you have to get to the indside of the pipe to remove the blockage.

 

[chard]

If it is sludge, would you suggest a 'sludge removal liquid'. What are the pro's and cons of using this?

 

[oilman]

Since no more air is coming out, there s no more water getting in.
If water does not get in there is a blockage.
If there is a blockage no water flows.
If no water flows there is nothing to move any cleaning chemical to the blockage.

I have used acid cleaner, and then given up as it wouldn't go up the blocked pipe.
I made a compression joint into a joint which can slide right over a pipe by removing the shoulder in the middle.
I cut the pipe.
I used a piece of flexible curtain wire to shove up the pipe to clear the blockage.
You could hold the wire in a drill so you could spin it as well.
I joind the pipe up again with the compression joint.

Just make sure you block the tank outlet first, or you will wish you had.
Mr. Muscle will not clear this one you will have to use a mechanical fix.
Forget the chemicals until watr moves again.

 

[corgiman]

If it is sludge, would you suggest a 'sludge removal liquid'. What are the pro's and cons of using this?

Sludge is probably a problem but not the one that is causing a problem, forget the sludge remover gfor a bit and re read OILMANS post and get the cold feed unblocked then sort the sludge is my humble advice

 

[COG]

As corg and oil said it sounds as if you have a bad blockage,sorry not you your system. sludge removers are not very good unless you have some circulation they don't tend to shift a solid resrtiction, plus you may have difficulty removing some water to add the cleaner.as oil said for the position of the blockage especially if its a cast iron boiler you may be better off draining it down and removing it physically, poss but can be messy,kind of job the apprentice runs away from

 

[MrRegs]

who runs this site why is there not a chat room ?

 

[oilman]

This site is fine (my opinion) I don't know what problems chat rooms have, but this site is ok.

Try this if you need a chat room.