How do I move a radiator to another wall?

Radiators are easy to unhook and hard to re-plumb. Almost all of the cost and difficulty in moving one is in the pipes underneath the floor, not the radiator itself.

Safety

What you'll need

• Two adjustable spanners and a pipe cutter
• Bowls, towels and plastic sheeting
• Pipe, fittings and clips to suit the existing system

Step by step

1. Work out which kind of move this is.Sliding it a metre along the same wall usually means extending the existing pipes. Moving it to a different wall means rerouting under the floor, which is several times the work.
2. Find out what the floor is.Suspended timber floors can be lifted and pipes run between joists. A solid concrete floor means chasing the screed or running pipes around the room at skirting level, which changes the job completely.
3. Check which way the joists run.Pipes run easily parallel to joists and awkwardly across them, since crossing means notching, which is regulated for depth and position. This single fact often decides where the radiator can go.
4. Think about where the heat is needed.Under a window is traditional because it counters the cold downdraught. An internal wall is fine in a well-insulated modern house. Do not put it behind where a sofa will sit.
5. Confirm the radiator is still the right size.A different wall may mean a different length available. Work out the room's heat requirement before buying, rather than assuming the existing radiator will suit the new position.
6. Get the room ready.Furniture out, floor covered with plastic then old towels. System water is black and stains permanently, and this job releases a lot of it.
7. Turn the heating off and let it go cold.Completely cold. System water runs at 60 to 80°C and scalds badly.
8. Drain the system or isolate the pipes.On many systems you can freeze the pipes locally with a proprietary kit and avoid draining. Otherwise the system is drained from the lowest drain-off point, which means refilling and rebleeding everything afterwards.
9. Remove the radiator and the old pipework.Close both valves, undo the unions with two spanners, drain into bowls, and lift it off. Then cap or cut back the old tails.
10. Run the new pipework.Shortest sensible route, properly clipped, with as few joints under the floor as you can manage. Every hidden joint is a future leak you cannot see.
11. Keep joints accessible where possible.A joint under a fixed floor is a real liability. Where one is unavoidable, note its position — a photograph before the floor goes back is worth a great deal later.
12. Mount the brackets before connecting.Into solid fixings, level, and at the right height for the valve tails to line up. Getting the brackets wrong makes the pipework fight you.
13. Refill slowly and bleed everything.Slow filling reduces trapped air. Then bleed every radiator in the house, starting downstairs, and check the pressure on a sealed system reads 1.0 to 1.5 bar cold.
14. Rebalance the system.Moving a radiator changes the flow through the whole circuit. Balancing with the lockshield valves is what stops one room baking while another stays cold.
15. Check every joint the next day.Kitchen roll wrapped around each connection overnight. Slow weeps do not show immediately and are far cheaper to catch before the floor goes down permanently.

Tips

• The pipe route decides the position, not the other way round. Check the joists before deciding anything.
• Photograph the pipework before the floor goes back. You will want it later.
• Rebalance afterwards. Moving one radiator changes the flow to all of them.

Common mistakes

• Choosing the position before checking the floor — A wall that needs pipes run across joists in a solid floor can turn a day's work into a major job, and the decision is usually made before anyone has looked.
• Burying joints under a fixed floor — Every hidden joint is a leak you will not find until there is damage. Keep joints minimal and accessible, and record where they are.

If it doesn't work

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