Running Pipes for Domestic Central Heating

[CHarr]

I have recently inherited a house which has only ever had part-central heating, and the radiator panels are in poor condition. The system was a DIY install in the late 1960s and has gravity fed HW & a pumped two-pipe heating circuit, but no thermostat other than on the boiler. The boiler itself has been renewed and is in good condition, so my intention is to extend the heating system by making it fully pumped with new controls (inc programmer, room & HWC thermostats & Y-valve), and to completely renew the heating pipe runs and radiators (with TRVs on all but two). My intention is to use underfloor plastic pipework, and for each radiator to fit t-connectors with copper pipe rising vertically to each radiator valve.

The floor joists run across the width of the house, so taking pipework from one side to the other will be easy (the house is empty, and I have all the floorboards exposed - access is not a problem); but getting pipes from front to back will require either notching joists, or drilling holes, and feeding the pipework through. For the first floor pipe runs, I wondered about the possibility of running pipes along the length of the wall below, just under the ceiling, and then covering the pipes with plaster coving, with elbows at each end taking the pipe back up to beneath the first floorboards. Is this OK? If I use plastic pipes, there don't need to be any joins between elbows, so the leak risk should be minimal.

 

[petertheplumber12]

On the first floor it would be easier to run the pipe work under the floor through joists with holes drilled for the plastic pipe. On the ground floor I would not choose plastic since it can be chewed by mice, It does happen. If using copper then notch but fit pipe clips to a piece of batten then screw the batten to the side of joist allowing clip to support pipe without touching the would and make sure they are insulated.

 

[ivixor]

Do it properly and drill the joists, the plastic pipe will obviously be very flexible so you don't have to worry much beyond having the holes roughly lined up. Try and minimise joints under the floorboards by using long swooping bends instead of elbows. Don't forget drain valves.

 

[Nige F]

Kind of agree with roughly lined up - but you need a 90 degree drill ( hired) to get the hole square to the face of the joist - it don`t work like sparkies cables that go through any old hole they punch through