Another cold radiator... but this one is a bit unusual!!

[kingandy2nd]

Hi All,

I know the cold rad question is asked loads on this forum, but my I can't find any post with the same problems as me so I need to post this one.

I has a new CH system fitted at the start of the year. The only rad that wasn't fitted was the towel radiator in the bathroom because the bathroom was fitted at a later date. The pipes were run into the bathroom by the plumber and left with an isolating valve on each of the pipes.

I've now fitted the towel radiator myself but I am having problems with getting it to heat up.

The flow pipe is hot, but the radiator only gets luke warm at best (and only really near where the flow pipe enters the rad). I've bled the rad and that's fine.

My thoughts were that I must have a dud TRV so I was going to replace these.

Thankfully I left the isolating valves in place when fitting the radiator so removing the rad was easy. I undid the pipework so the TRVs were still attached to the radiator.

However, when I've gone to drain the radiator both TRVs seem to be fine and drain water from them when opened, and stop draining when closed.

The unusual thing (well I thought to) was that even with either TRV open I had to also open the bled valve before the water would come out. I do understand the need for air to be able to enter the system to allow the water to drain, but I had expected the water to come out in glugs (much like when you turn a bottle of water completely upside down). Thought I should mention this as it might be useful info for those more experienced than myself.

It's not the highest radiator on the system, nor the last on the circuit - the radiators after this one heats fine.

Any ideas on what's wrong will be gratefully received. Thanks!

 

[Bahco]

Try all these and lose the isolating valves and let us know how you get on.

 

[JPC]

i know why bahco would say loose the iso's...but no need...they let plenty enough water through for 1 rad.
if you open 1 iso at a time does water squirt out as expected or is the blockage on one side ?
it does sound like a blockage of some kind.
i take you u fitted 1 trv and one LS (you mentioned 2 trv's)

 

[kingandy2nd]

Hi guys, thanks for your input.

Sorry - my plumbing inexperience is coming out here. I’ve not actually fitted TRV’s, I bought and fitted a set of Regis Decorative Straight Radiator Valves.

(I tried to link to the item on the B&Q website but the link keeps bringing back different products - the product code is 5013866068898 if you want to search the website for the actual item used).

I recall reading somewhere that it’s not strictly important to have TRV’s on the bathroom radiator – is that correct or am I making that up?!?

I suspected it might be a blockage, but will try turning one valve on at a time to confirm this.

How effective are these sludge removers you can buy? Can I use this stuff while the radiator is off system?

As I’ve already isolated the radiator, I’d prefer to attempt to unblock the radiator on it’s own, rather than drain the whole system and then add the additive. Would that work, or does the sludge remove have to be used in a working system and get heated up in order to work properly?

Also, the radiator is one of these ladder style radiators, so wouldn’t a lot of the pipes have to be blocked in order for the radiator not to function properly?

Thanks again!

 

[Rico99]

Hi there,

I know this may seem strange but SOME twoel rads can only be used 1 way up.

There is usually some kond of marking on it to show which way up it should be.

Also what kind of system are you on. Sealed or Open vented.

Rico

 

[kingandy2nd]

There were no markings on the radiator to indicate which way up to fit it unfortunately.

I believe the system is sealed although I'm a bit unsure of the different. It's a new system with a biasi combi condensing boiler - no tank in the roof or elsewhere. Is that sealed?

Thanks again

 

[kingandy2nd]

Ok, just a quick update.

I've check the pressure of the water coming out of the flow and return valves and that's fine so it must be something wrong with the rad itself.

Any thoughts on the effectiveness of sludge remover welcomed

 

[spacethegas]

as the installation is not very old sludge should not be a problem.

have you not considered that it is piped up incorrectly. both feeds coming from the flow or return, rather than one from each.

 

[Bahco]

Have you tried the FAQS checklist

 

[kingandy2nd]

Hi All,

Thanks for your advice! For info the return pipe stays cold, so I think it's plumbed correctly. Also I had checked the FAQs before posting

However, after an afternoon of fun and games I am pleased to inform you all that the radiator is now working again.

I took the rad into the garden, filled it with Fernox sludge remover and hot water. Left it for an hour and then used my pressure washer to blast water into the rad for about 5 mins (unconventional perhaps, but good fun).

I then drained the rad, flushed though for a few more minutes with water from the hose and drained again.

Then took it back into the bathroom and fitted it. Once filled and bled -hey presto, a nice warm rad!!

It must have been blocked, which is strange for a new rad but thinking back now when the plumber left it for me it wasn't boxed... perhaps it wasn't quiet so new after all!!

Thanks again for all your ideas!!