Pipes Pipes Pipes

[Broadie451]

Hi we have a central heating system plumbed in 10mm Throughout I want to upgrade it to 22mm for the main run then reduce the pipe down to 15mm to each rad. At the moment each rad has a 10mm pipe to the old TRV and lock shield valve. Is it worth keeping the run in 15mm to the rad or would it be ok to reduce the pipe down further to 10mm under the floorboard near to the 10mm riser to the rad.
Any advice would be greatly appreciated
Cheers

[Old_Geezer]

No expert, but I assume the issue is that water is not getting through fast enough to heat your rads well. In which case I'd be thinking that why risk restricting the flow by having a smaller pipe at the end ?

I'm just a little concerned that if the rads are designed for 10mm then maybe changing that last bit will be minimal benefit, but if you are doing the pipe replacement job anyway ?

Have you considered changing the rads also so they connected to a larger bore ?

[Broadie451]

hi thanks for the answer yes I would like to change the rads and the TRV's in the process. I think there is a lot of sludge in the old system that needs to be flushed out as well.
I want to change the boiler but I can see that happening until after Christmas now due to plumber availability.
So the plan is to do as much of the pipework as possible before the install of the new boiler, and leave the runs "dry", then swap over to the new system.

[The Builder]

With 22mm of flow to each rad, Broadie, you'll have no problem reducing to 10mm for the rads.

[Broadie451]

Thanks very much