Have spent all day balancing the system and still no heat!!

[Coolhurst]

Radiators fitted to the ground floor of my new, part-finshed, two-story, extension refuse to get warm. We're keen to get some use out of the room during xmas hence the part-finished state.

Our plumber thought adding one radiator to the yet to be completed upstairs might help get heat down to the new rads but to no avail (Btw, he has also fitted a bigger pump to the system as part of the original works).

Today I attempted to balance the system (turned TRV to max. and the valve on by a quarter turn). I then worked my way along all the radiators to balance them. All working perfectly aside from the four new radiators which don't appear to be getting any heat at all. No heat is getting to any of the pipes feeding the rads. I've now discussed with our plumber who is thinking we may need to add an additional pump to help heat getting to the end of the house. I guess this makes sense but wondered if anyone had ideas of anything else I could try before spending out on the additional pump.

Cheers.

 

[Whitespirit66]

Do the new rads heat up when other rads are turned off?

Can't understand the logic of adding an extra rad upstairs to encourage the cold ones downstairs to heat up.

You will also need to give more system details - boiler, type of system, no of rads, etc, etc, etc. Also, how has he joined new rads to existing system?

 

[Coolhurst]

Yes they do but only when all other radiators are turned off.
Grant boiler (90-120) which is in fine and healthy order, feeding Rads- 6 ground floor (plus another 4 new ones that don't work) and 8 radiators upstairs (plus another extra one added into upstairs of new extension to try and help with flow of heat back down to new radiators?
New radiators are apparently at the end of the line/run.
Not sure about how he's added radiators to system but appears to be waiting for flow for upstairs coming down into new extension? Are there any questions I can ask him to give better info?
Really puzzling that all radiators are piping hot apart from these four brand new ones!

 

[leakydave]

Surely either an air lock or they haven't been piped correctly

 

[Steelmasons]

Our plumber thought adding one radiator to the yet to be completed upstairs might help get heat down to the new rads but to no avail (Btw, he has also fitted a bigger pump to the system as part of the original works).

A change of plumber might be the first port of call.

 

[Blagard]

Today I attempted to balance the system (turned TRV to max. and the valve on by a quarter turn).

If I read you correctly you have only opened the new lockshields a quarter of a turn when they are at the end of the run?

End of run Rads are the ones that need the lockshield valve open more than the rest, sometimes fully open especially if on the end of drop pipes from the circuit above

 

[ALEC1]

all piped on 15mm no doubt,

 

[Coolhurst]

Thank you all for your replies. We did open the valves on new radiators fully but still nothing. Now going to try this morning to open only those radiators and turn off all the other radiators in the house - if /when the new radiators heat up then start turning on the others on the way back towards the boiler. Will that help or tell us anything?

We've used this plumber for a while and he comes recommended but maybe he is at fault, just want to be sure we've exhausted every possibility- he's talking about putting in an extra pump near to the new radiators and I'm loathe to do that!

 

[ALEC1]

what size is the pipework...

 

[mogget]

what size is the pipework...

Indeed.

 

[Coolhurst]

Pipe work is apparently 28mm through house going to 22mm then down to 15mm into rads? As I say, rads have got warm when only rads on in house??! There is a tricky area upstairs where pipes are going up and over a step then round a corner- could this be an issue? Could there be a block?

 

[mogget]

If I underttand you correctly, if there is a loop upwards in a pipe, which could trap air, it would make sense to put a manual air bleed in.

 

[Coolhurst]

Thank you for all these questions and for taking an interest! Yes that's why he put in the extra radiator upstairs to act as a vent. Do you think there could be a restriction somewhere and how can I track it down?

 

[mogget]

I don't know your boiler, does it have a separate pump or is it internal?

 

[mogget]

And is it a sealed system or open vent?