New radiator not getting hot

[maisbitt]

Zombie thread resurrection to save setting up a new one.

We had a wall knocked out between kitchen and garage conversion. On that wall was a small radiator. The tails were hanging for ages, waiting for a plumber that never turned up over a period of a month. Further down the wall, I'd hung the new radiator, waiting for the plumber.

So I thought I'd have a go. Created new tails, bent and passing along the wall to the new valves, fitted like for like to match the old tails e.g. lockshield on new piping continued from old tails that had lockshield on, same for thermostatic valve tail.

Everything's on, other radiators are piping hot and only the lockshield valve piping is warm,not the thermostatic valve piping.

It's a new fancy designer radiator, so presuming it only works one way (I followed the flow directions) and the original housebuilding plumber plumbed the valves in backwards. I have bled the radiator for air, so it is full.

Before I go cutting a gap in the 2 pipes and criss-cross the cut ends with couplers to switch flow (on the assumption that the old radiator valves were on backwards and it didn't matter on that radiator), has anyone got anything else for me to try?

Lock valve is open, thermostatic valve is fully open. Radiator is bled.

 

[JohnD]

fancy designer radiator

Show us a photo of this radiator please.

What are its pipes connected to?

 

[maisbitt]

There is an arrow from the thermostatic valve side (right on photo) to the TRV valve side for direction of flow. The air bleed valve is above the TRV valve (left on pic).

10mm micropore as per all plumbing downstairs.

These are piped to the original pipework as cut from the tails of the old radiator.

Only the pipework to the TRV valve gets warm, the pipework from the thermostatic valve does not.

No noises, assuming the tails were wrong way around on old basic radiator and baffles on new one are killing flow? If tail to TRV is hot and the other is not, does this indicate that the feed is to the TRV valve?

 

[picasso]

Take the head off the Trv and make sure the pin isint stuck, if that’s not the problem close all the other rads and see if you can force the flow round the cold rad.

 

[maisbitt]

Take the head off the Trv and make sure the pin isint stuck, if that’s not the problem close all the other rads and see if you can force the flow round the cold rad.

The TRV is an Allen bolt type, the whole allen head moves up and down with a range of about 7mm height. Does that make the TRV comment redundant?

I'll close all the other rads and try. Thanks.

 

[denso13]

The TRV is an Allen bolt type

The TRV is the one with the thermostatic head. The other one is a lockshield valve.

 

[maisbitt]

The TRV is the one with the thermostatic head. The other one is a lockshield valve.

Yep, I read lockshield when you said TRV. TRV head disconnected and reconnected. All other rads off - little spurty noises coming for inside the new radiator as if flow isn't coming easy and maybe it's not all full. As it has a 13 litre capacity, it might take a while.

 

[denso13]

Only the pipework to the TRV valve gets warm, the pipework from the thermostatic valve does not.

Do you mean the lockshield pipework gets hot? That could be the flow.

 

[maisbitt]

The radiator is fairly hot now, except the last vertical bar nearest the TRV, which is probably 10C cooler. The Lockshield valve piping is significantly hotter than the TRV piping.

Presumably this either confirms flow is wrong way around, or I had a big air pocket (as per the squirty noises within the radiator at thr TRV end) which has now been forced along the system?

I'm presuming hottest pipework is inlet pipework that should be feeding TRV end and not lockshield end, confirming flow is opposite to what it should be?

 

[denso13]

I'm presuming hottest pipework is inlet pipework that should be feeding TRV end and not lockshield end, confirming flow is opposite to what it should be?

Yes, seems like it.

 

[maisbitt]

Yes, seems like it.

Would you suggest swapping the pipework around immediately or seeing what it's like warming up from scratch now that water is everywhere it should be. Presuming the flow will always be crap if left as is.

Trust my luck to replace like for like and the original plumber had the valves for the old radiator wrong (but it didn't matter on the old one).

 

[denso13]

Would you suggest swapping the pipework around immediately or seeing what it's like warming up from scratch now that water is everywhere it should be.

Up to you really, if you are happy that it is hot enough then no real need to change it. See how it goes for a few days, especially heating up from cold.

 

[maisbitt]

I've just done the switcheroo between the pipe feeds with a few compression couplers. Checked for weeping leaks and nipped up the nut another 1/6 of a turn - conformed leak free and radiator warmed up quickly. Both inlet and outlet feeds are toasty. The radiator is cooler (not by much) at the bottom 1/5 than everywhere else - presumably and oddity of the structure of this fancy radiator and direction of flow?

Either way, it's functioning as per expectations now.

Thanks for the help. I may replace most of my existing radiators in future - I will check which pipe gets hottest quickest to determine inlet rather than relying on the housebuilder's plumber having put the shield valve on the right end (which they clearly didn't here).

 

[picasso]

Luckily I am only here making up the numbers...