New Rad nowhere near as warm

[skybluescooby]

Just had a 4m x 4m sun lounge built with tiled roof and insulated walls,
A new radiator was fitted and was fed from the radiator in the bedroom directly above the new room.
It runs from the bedroom wall, through and into the roof void and down the furthest wall from the house where the rad is fitted.
The question is, why is this rad not the same temp as the house rads.
The plumber left as soon as he felt it heating up, we rang him a day or two later and he said it's cold because it's reflecting the temperature in the room, at the time the room was drying out having been plastered. windows were left open to nsure a steady flow of air as instructed by plasterer.
Weeks later the room is dried out, decorated and a fitted floor down but still the thing is luke warm.
The house rads are red hot and when i check the new rad its luke warm at the top but cold at the bottom.
I have bled it once which didnt work and i noted a sploshing sound when i removed it from its wall mount to decorate behind it.
Its fed from i believe a 10mm plastic pipe.
The system is 10 yr old and feeds 11 rads throughout our 3 bedroomed house
Any suggestions will be welcomed as the plumber is calling back tomorrow to take a look
Regards

 

[gigz]

Close some of the other rads off, see if the rad in question gets hot. If it does it just needs balancing, if it doesn't pipes maybe partially blocked check that both valves are fully open.

 

[Agile]

I am sure this plumber will immediately realise that he forgot to rebalance the system and will sort it out for you quickly and effectively.

Tony

 

[uug197h]

Taping to another radiator dose not always work as its not in the circuit it is spurred off water like air will take the easyest path and coming of another rad with t's is not the best way as the water will by pass the new pipe work at best this will only be lukewarm

 

[skybluescooby]

Thanks for the info guys n galls,
Plumber didn't turn up and has rescheduled for Monday
I will take the advice given and have a tinker over the weekend, any more sugg's gratefully received

 

[skybluescooby]

Quick update, Turned the rad thats feeding the new rad off, within 30 minutes or so the new rad was the hottest it's ever been, turned exsisiting rad back on and new rad soon cooled.
Is this a balancing problem and if so how does it work.

 

[Bahco]

Look in the sticky FAQs post, fifth one down.

 

[skybluescooby]

Plumber came out an balanced all rads, waited half n hour and no difference felt, he then said i need a new pump ???
I have also been told by another plumber type person to fit a thermostatic valve on the supply rad so it diverts the heat when at the desired temp,
Whats everyones thoughts on this

 

[gavinda]

sounds like a pack of lies... try balancing it yourself as suggested before.. its really quite easy. but balance the whole system. then think about the pump.

 

[skybluescooby]

no expert here but after reading the sticky and then following the plumber round (not in a psychotic way) he appeared to do it as per the sticky ?

 

[stevesey]

Should be cured by balancing - just try tweaking the hottest rads down a bit by bit to see if that helps.

Also what speed is the pump on - most have 3, turning it up may should help - but exhaust the balancing possibilies before resorting to that.

 

[bribhoy]

What size of pipework feeds the bathroom rad? if it is 8/10mm and there is a bit of a pipe run to the new rad, all the balancing in the world may not help...may need new rad teed of a larger supply (15mm minimum, 22mm preferable) THEN system balanced