New Radiator - Luke Warm

[b830ag2]

Hi all,

I've just installed a new radiator in a house we've just moved into, and it's a lot cooler than ALL the others in the house, downstairs and upstairs. The others are quite hot to the touch and cannot touch for too long.

Apparently there used to be a radiator in the this room years ago, but the previous owners had it removed so that they could fit in a bit cabinet. They just cut and capped the pipes and so when installing the new one i just used the existing pipes. Had to do a bit of work to re-route them to the new, smaller, radiator, but nothing significant.

Anyway, got it all up and running but the radiator only gets lukewarm. Not sure why. System is clear (powerflushed by previous owners not too long ago), and all other Rads piping hot. The new Rad is downstairs, the boiler is downstairs, the pump is upstairs.

I originally put in a TRV, but I had a bad experience with one years ago, so decided then to replace it with a normal valve. This did improve things slightly, but not really enough.

I now can't decide whether the system needs balancing, or whether there's another fault. Anyone help?

Oh, just one more thing, the flow pipe and the valve are absolutely boiling to the touch, but all of the radiator, and return pipe, is luke warm. Can't understand why it's so hot at the valve but not that hot in the rad, even at the end with the hot valve!

Any advise would be appreciated.

Thanks,
Andy.

 

[gigz]

Doubt very much that the person who did the powerflush took the caps off and flushed the two dead legs (pipes where the original rad was) you would be better off taking the rad off and manually flushing the pipes into a bucket (or ideally a hosepipe if theres a drain off) give it a good few minutes, then balance the rest of the rads (see F.A.Q.s)

 

[b830ag2]

Yes, I doubt the capped stems were flushed too, as the soldered caps looked liek they had been there for a while! however whilst 'de-capping' and fitting isolation valves (didn't drain the system because I used a pipe freeze kit), I did let a certain amount of water drain out of these pipes whilst 'testing' the isolation valves.

I will attempt to balance the system, and will post an update, however I was confused as to why the obvious difference between this radiator temp and all the others, and also I wasn't sure if this Rad was the furthest from the boiler. It is downstairs, in the next room to the boiler...and all the balancing posts refer to the Rad furthest away. I am a competent novice at basic plumbing tasks but do not have any idea as to the routing of the piepwork in my system. Are the Rads upstairs first to receive the water from the boiler? Thinking about it though, the Radiator in question is clearly not the furthest away, as both pipes were previously capped...therefore the return pipe could not have been the last one in the system, otherwise there would be no return to the boiler! I think.

Cheers,
Andy.

 

[JohnD]

old sediment can form a hard blockage, especially in pockets of low flow.

if the balancing doesn't work, you could add a sediment cleaner such as Sentinel X400. as long as there is a bit of flow (not a complete block) it will soften and loosen the sediment. You will know if it is loosenig sedminent because the water will go black.

 

[b830ag2]

I see.......

Got pretty good flow though, when opening the isolation valves early doors, I accidentally soaked the underfloor wall when testing as it spurted out v. fast.

Thanks.

 

[topgazza]

Faulty rad ?

I know they are simple simple things but worth taking off and filling up and checking...its odd that both in and out flows are hot but that could be conduction of course......

 

[JohnD]

...return pipe, is luke warm....

 

[topgazza]

That'll be the one then....

Still...just a thought.....