Poor Heat Output on Downstairs Radiators

[scoobydo123]

Yes close the rads that are getting hot some more. It is not just a fact of 1/4 a turn on them all, close so no output then open "slightly" obviously they wont go instant hot so come back in half an hour to see if flowing

 

[GoodDIYjob]

Yes close the rads that are getting hot some more. It is not just a fact of 1/4 a turn on them all, close so no output then open "slightly" obviously they wont go instant hot so come back in half an hour to see if flowing

OK Will try, thanks. Only problem is they are quite noisey at 1/4 turn, if I close some [more] it might not be very usable in bedrooms due to noise. Will see how it goes with the heat though as experiment. Thanks.

 

[scoobydo123]

Ok and is this 15mm pipework or smaller, can you see if the pipe runs are 22mm teeing off to 15mm like it should be. Or maybe someone has been a bit naughty and piped them in series which will cause issues

 

[D_Hailsham]

The noise you are talking about when the LS valves are almost closed is due to the pump set to give a high flow rate. It may be possible to set the pump to a lower speed so reducing the noise. This will all depend on which combi boiler you have. Which one is it (make and model)? The system would have to be rebalanced if the pump is set to a lower speed.

 

[GoodDIYjob]

Ok and is this 15mm pipework or smaller, can you see if the pipe runs are 22mm teeing off to 15mm like it should be. Or maybe someone has been a bit naughty and piped them in series which will cause issues

The drops to rads are all 15mm. The flow and return visible at the boiler is 22mm in the cupboard. There is a flow and return visible in boxing in, running downstairs just outside the kitchen door in 22mm. As to actually what is teed into downstairs and if any backbone for flow and return in 22mm exists past each rad, impossible to say without lifting laminate floor and floor boards.

It could be something dodgy has been done with pipework downstairs. That's where my thoughts have ended up. The rads that are located off that 22mm pipework running down the wall, on ground floor level, are all very close to the position of where the flow and return run down the wall, all within about a 2M radius based on the walls that have been chosen to site radiators, and for example the radiator in the front dining room, is on the rear wall not underneath the window, as normally preferred but presumably was a easier to pipe.

The noise you are talking about when the LS valves are almost closed is due to the pump set to give a high flow rate. It may be possible to set the pump to a lower speed so reducing the noise. This will all depend on which combi boiler you have. Which one is it (make and model)? The system would have to be rebalanced if the pump is set to a lower speed.

Yes, I don't think our combi has a speed selection, it is a Biasi Garda M90F 32S boiler with a Wilo pump but only one speed as far as I can see...

Thanks


.

 

[GoodDIYjob]

Just to hopefully close out this thread....

So after playing with balancing a little bit more and getting the radiators slightly better but still the two large downstairs struggled to be more than luke warm half way down their height.

Then, the last few days our boiler has been playing up a bit and I changed the boiler thermostat temp setting for the CH circuit. It is now on no5 about 75C and the problem radiator is very hot, like I've never experienced before. I could close it down from fully open to give the other large rad more heat but I haven't yet.

The reason why we generally had the boiler lower is little children and bare skin in bedrooms getting dressed etc. but they are getting a bit bigger now, so will have to be more careful we will make them aware. I could restrict flow more on rads in their rooms, but then their rooms will be cold!

Feel a bit silly that the answer to finally get good heat was turn up the boiler. Still the hose out, cleaner, 2 new rads and TRVs upstairs can't have hurt and probably all needed doing!