Moving heating pipes

[Graemevw]

Could do with a bit of advice if poss.

Our house has a boiler and hot water tank. Heating was fitted after the house was built, by the council.

The heating pipework upstairs is all under the floor boards, but downstairs they have added a seperate drop down for each rad and run the pipes above the skirting.

I want to re-pipe downstairs under the floorboards.

There are 4 rads upstairs and 3 downstairs. The drops down to the downstairs rads seem to alternate between the upstairs rads. Its 22mm under the floors with 15mm drops to the rads.

What i wanted to do was leave the first drop down (in the utility) and then run the other 2 downstairs rads from this too. Make sense?

That would mean there would be one or 2 rads upstairs, then it would split with one drop going down to feed the 3 downstairs rads and the other half going to feed the remaining 2 upstairs rads. Sound ok? If so, should i re-pipe the drop in 22 and do all the downstairs underfloor pipework in 22 too, then reduce to 15mm for the pipes up to the rads? Or just run all downstairs in 15mm.

Thats assuming its ok to split the system like this.

Rads are all parallel by the way, not series.

 

[Graemevw]

No thoughts? Or havent i explained it very well?

 

[Graemevw]

My current thoughts are to split the 22 into 2 runs, one upstairs, one downstairs, then tee off in 15mm to each rad.

Will end up like this bad paint drawing, but with a hot water tank obviously.

 

[denso13]

Looks fine. You also have to take zone valves (if any) and hot water cylinder connection into account. But if you are simply using one of the existing drops (changed to 22mm) to repipe under the floor then it will be ok.

 

[dcawkwell]

Try it with the existing 15mm drop first this may be enough.
But should work.

 

[Graemevw]

Got a number for a friend of a friend who's a plumber. Gave him a ring and he said the same, just use one of the existing 15mm drops and run the other 2 rads from that too.

Hot water cylinder is after boiler, before first rad and i dont think we have any zone valves.

Thanks.