How much does radiator replacement cost?

The cheapest radiator job is a straight swap: the new radiator is the same width and has the same pipe centres as the old one, so it hangs in the same place and connects to the existing pipework with little or no alteration.

For that, most plumbers charge £100–£200 in labour for the first radiator. A standard double panel radiator costs roughly £60–£200 to buy, so a typical supplied-and-fitted price lands around £150–£450.

The work involves isolating or draining the radiator, removing it, fitting new brackets, hanging the new one, connecting the valves, refilling, bleeding and checking for leaks. Allow one to three hours for the first one.

If the pipe centres do not match, the plumber will need to adjust the tails or alter the pipework under the floor. That is common when replacing an old imperial-sized radiator with a modern metric one, and it can add an hour or two.

The radiator itself. A plain white panel radiator is cheap. Column, vertical, cast iron style or designer radiators cost much more to buy and are heavier and fiddlier to hang.

Whether it moves. Keeping it in the same spot is quick. Moving it to another wall means lifting floorboards, running new pipe and making good, which turns a two-hour job into most of a day.

The wall. Brick and block take brackets easily. Plasterboard or stud walls need fixings into timber or extra support, especially for heavy column radiators.

Your system. On a combi or sealed system the plumber may need to drain down and repressurise. On an older open-vented system with a header tank in the loft, draining and refilling is similar but the tank may need attention too.

The valves. Reusing good valves saves money. Old seized valves are better replaced at the same time, since it costs little extra while the system is already drained.

A rough estimate is easy once you know what you are buying.

1. Price the radiator you want. A standard double panel is £60–£200; a column radiator can be £250 or more. 2. Add £100–£200 labour for the first radiator, and £80–£150 for each extra one done on the same visit. 3. Add £40–£90 per valve if you want new TRVs. 4. Add £250–£600 for any radiator that needs moving to a new position.

Example: replacing three tired panel radiators in bedrooms with new ones of the same size, plus new TRVs on each. Radiators about £300 in total, labour about £280–£450, six valves fitted as part of the job about £120–£240. That is roughly £700–£1,000 all in.

On BidMyJob you can post the job with photos of each radiator and its pipes, and local plumbers bid, so you get prices for your actual setup rather than a guess.

Every radiator has two valves: one controls the flow and the other, the lockshield, balances the system. Thermostatic radiator valves (TRVs) let each room be set to its own temperature and are worth fitting where they are missing, except usually in the room with the main wall thermostat.

Swapping a radiator does not always need the whole system drained. If the existing valves close properly, the plumber can isolate the radiator and catch the water from it. If the valves are old, leaking or do not shut off, a full drain down is needed, which adds time.

Whenever a system is drained and refilled, corrosion inhibitor should go back in. It protects radiators and the boiler from sludge. A good plumber will do this without being asked, but it is worth checking it is in the quote.

The type of heating system makes a small difference to the job.

Combi and system boilers run as sealed, pressurised systems. After any draining the plumber refills and brings the pressure back to the right level, usually around 1 to 1.5 bar cold, and bleeds the radiators.

Older open-vented systems have a feed and expansion tank in the loft. Refilling is similar, but if the tank or its ball valve is in poor condition the plumber may suggest fixing it while there.

Replacing a radiator does not involve the boiler or gas supply, so it does not need a Gas Safe engineer. Any work on the boiler itself does.

If radiators are cold at the bottom, take a long time to warm up, or the water that comes out when bleeding is black, the system probably has sludge in it. Fitting a new radiator into a dirty system means the new one will fill with the same sludge.

A power flush pumps cleaning chemicals through the whole system at high flow and typically costs £400–£750 depending on the number of radiators. A cheaper chemical flush, done over a few days with the boiler running, is sometimes enough for milder cases.

A flush is not needed every time a radiator is replaced. It makes sense when there are clear signs of sludge, or before fitting a new boiler, where most manufacturers expect the system to be cleaned for the warranty.

Do several radiators in one visit. The first one carries most of the set-up time, and extra radiators are much cheaper each.

Match the size and pipe centres. A radiator that fits the existing pipes saves pipework alterations.

Buy the radiator yourself if your plumber is happy with that, but check the size, output and connections with them first.

Replace old valves while the system is drained, rather than paying for a second drain down later.

And leave the radiator where it is unless moving it really improves the room.