newly fitted flat panel radiator cold

[Reno1ted]

Hi,

I realise this is a common problem, but mine is slightly different to what I have read and I have tried most of what has been suggested.

I have a radiator like this one:

Except with more panels. But same design.

It has only been fitted last year, but has never really got hot at all. It had a TRV fitted, and I read that this type of Radiator should have just a normal tap valve, so this week I fitted one of those, but still it will not get hot. This at least rules out a dodgy TRV! So then I shut down all the other radiators, opened the valves fully on both sides of the rad, set the boiler to full wack, and its still cold.

The thing is, the pipes in and out of the radiator is really hot, as it too hot to keep your hand on. And other normal radiators in the house get too hot to touch when on full.

When I bleed it, water does come out under pressure, but its stone cold. And a bit dirty.

I have my boiler set to 1 bar, but then tried it on 1.5 bars, still no joy.

The bottom pipe that runs along the radiator (that the panels are connected to) does get warm, and the middle two panels get a bit warm till about 1/4 of the way up, but when I say warm, its not hot.

I would have thought if it was blocked, one of the pipes wouldnt get hot?

Also there are isolation valves on the pipes, but the pipes are red hot after that point. They are open fully.

The pipes run along above the floor, when I did the house up, we chopped the pipes at the point them come out of the floor, and covered them till I was ready to do that room, then ran chrome covered pipes to where the rad is (due to being above floor, looks better).

Willing to try anything !

Any thoughts? If it is a blockage

 

[tryitandsee]

Have you piped up the rad with flow and return, you may have piped it up with both flows!

 

[Reno1ted]

Have you piped up the rad with flow and return, you may have piped it up with both flows!

I have used the same 2 pipes that were going to the old radiator. The only difference is that I cut the pipes where they come out of the floor (in the corner of the room) and blocked them with isolation valves, then when I got the new rad, i connected it up with new pipes, but where those new pipes connect is to the same pipes that were there already.

Though I didnt actually ever use the old radiator, it was part of an established fitted system, so I am sure it would have worked ok with its own flo and return.

Could there still be a way I have given it two flows?

 

[kevplumb]

I cut the pipes where they come out of the floor (in the corner of the room) and blocked them with isolation valves,

did you use full bore valves

 

[tryitandsee]

This may be a gravity fed rad, hot water rising worked ok for your old rad, but for whatever reason, won't circulate with this one.

 

[tryitandsee]

Reading your post again, my gravity idea is not an option.
You are sure both rad valves are opening!

 

[Burnerman]

Either a faulty valve not opening or a blockage in the return pipe, I'd guess

 

[JayJay1978]

I read somewhere on a forum (maybe this one?) that these designer rads are very fussy about having the flow and return reversed, I'm sure this guy swapped them round and it worked.

First try cracking open the union on the return and drawing some water off and see if that works.

Ideal job for wec & dry vac

 

[Reno1ted]

Hi,

I think the isolation valves are ok.

If it is a dodgy valve then it has to be the right hand side one, as the left hand side one i replaced from TRV to just normal tap one, to have 2 dogdy would be unlikely.

Blockage wise, both valves get pretty hot. Maybe a block in the rad itself? Whats the process to elminate each, do i switch the valves off, take the rad off, and then with bucket in hand open each one and see whether i get soaked ? Also its just weird that both sets of pipes get red hot, i dont know much but doesnt hot water come in one pipe, through the rad, then out the other? So if the rad was blocked, or a valve was bust, wouldnt one pipe be cold?

Thanks for the replies guys !

 

[Reno1ted]

I read somewhere on a forum (maybe this one?) that these designer rads are very fussy about having the flow and return reversed, I'm sure this guy swapped them round and it worked.

First try cracking open the union on the return and drawing some water off and see if that works.

Ideal job for wec & dry vac

Sorry bud, dont know what you mean?

 

[gigz]

Turn boiler off, close the valves and disconnect the rad, then open the valves into a bucket to see if you have full flow out of both pipes. Let us know what happens.

 

[tryitandsee]

These types of radiators are a warren of welded tubes, often small bore. Perhaps when doing other work on system crud has got into the rad and blocked the various waterways and it is just passing through the pipe that links the two valves at low level.

Isolate the rad from the two locksheilds, take it out into the garden and give it a good blast through with whatever you can rig up.

 

[Reno1ted]

Ok, Ill take the rad off the wall this weekend, and check both valves with the bucket, and give the rad a clean out as suggested, then report back.

Couple of questions. If as the above poster suspects, its blocked so the water is just running down the connecting pipe at the bottom and back out, what might be the best way to blast the thing clean. I am thinking a hose or power jet will just clear that same pipe and not get around the whole radiator? I do have a hose attachment in my garage which I can fit and then fill the rad up to high pressure, then pull the hose off and let the water out? Should I maybe add some chemical that will remove the grime etc?

Also any tips for taking the radiator off without getting water everywhere? Obviously I will close both valves, but will water not just poor out of the radiator when i start to unscrew it? Or is it as simple as unscrewing it and draining it slowly?

Again guys, many thanks. I am sick of a cold front room, and I want to beat this thing, its my new mission.

 

[tryitandsee]

Perhaps a stupid question, but I take it the bleed nipple/screw for this rad is located at the top

 

[gigz]

Also any tips for taking the radiator off without getting water everywhere? Obviously I will close both valves, but will water not just poor out of the radiator when i start to unscrew it? Or is it as simple as unscrewing it and draining it slowly?

Put a dish and some towels underneath. It'll only squirt until the pressure is released, crack the nuts then stick your thumb over the ends and pour outside.