Heating & energy
Radiator replacement cost calculator
Swapping one radiator for another of the same size is one of the most useful DIY plumbing jobs, and is not notifiable work. Nothing is done to the boiler or gas. If a radiator is not heating up, bleeding it takes minutes and is often all you need.
- Full DIY
- £330
- Smart Hybrid
- £650
- Full Trade
- £720
Typical mid-range job, Midlands rates. Yours updates below.
Updated November 2026. Estimates based on typical UK prices.
Cost calculator
Price this job three ways
Answer a few questions and watch the numbers move. Nothing is saved or sent anywhere.
Smart Hybrid saves £70 against a full trade job.
Smart Hybrid
You take on what you can, a trade handles the rest.
£650
- Materials
- £330
- Labour
- £320
- Drain down, swap radiators and refill£320
- You have not taken on any of the work yourself, so this matches the full trade price.
- Check each new radiator’s heat output suits the room. A bigger room or a cold, north-facing wall needs more.
- Swapping a radiator like for like leaves the boiler alone. Any work on the boiler or gas pipework needs a Gas Safe engineer.
Turn this into a plan
Get the order of work, who to book and a budget tracker, all editable.
Order of work for this job
A typical order. Always confirm timing with whoever you book, since some steps can overlap.
- 1
Fitting
- Drain down, swap radiators and refillBook a plumber · ~1 day
How we worked out the materials›
- Radiators£2602 × £130 = £260
- Valves (thermostatic and lockshield)£441 valve pair per radiator × 2
- System inhibitor£161 bottle protects a typical home system
- Sundries£10PTFE tape, fibre washers and dust sheets
Estimates only, based on regional averages. Always get 2 to 3 written quotes from local trades.
The price
What affects the cost?
- 1
Size and output
Bigger radiators with higher output cost more. Size depends on room size, insulation and windows.
- 2
Type and finish
Standard panel radiators are cheapest. Designer, vertical and towel radiators cost a lot more.
- 3
Valves and fittings
New thermostatic radiator valves (TRVs) and lockshield valves are usually fitted with a new radiator.
- 4
Moving a radiator
Changing position means new pipework and possibly lifting floorboards, so costs rise quickly.
- 5
Draining the system
Replacing a radiator on a sealed system needs draining and refilling, which takes time.
Be honest with yourself
Can you do this yourself?
You can do
- Bleeding radiators
- Swapping like-for-like with the same pipe centres
- Fitting new TRVs
- Painting or decorating around the radiator
Leave to a pro
- Moving or adding radiators and new pipework
- Anything involving the boiler, gas or flue
- A system pressure or power flush problem
- Underfloor heating
The rules
Replacing a radiator is not notifiable, but any gas boiler work needs a Gas Safe registered engineer. Never touch the boiler itself.
DIY guide
How to replace a radiator, step by step
Tools you'll need
- Adjustable spanners and a radiator spanner
- Bleed key
- Bucket and plenty of towels
- Level and drill
- PTFE tape and a pipe cutter
Materials
- New radiator and wall brackets
- Valves (TRV and lockshield)
- PTFE tape or fibre washers
- System inhibitor
- Dust sheets and towels
- 1
Measure and buy the right size
~0.25 daysMeasure the old radiator width, height and the distance between the pipe connections (the pipe centres). Buy a replacement with the same centres so it connects to the existing pipework.
Tip: Take a photo and measure the bracket positions before you drain anything.
- 2
Turn the heating off and let it cool
~0.1 daysSwitch the heating off and wait for the system to cool. Protect the floor with dust sheets and towels, because dirty water will come out.
- 3
Close both valves
~0.1 daysClose the thermostatic valve and the lockshield valve at the other end. Count the turns on the lockshield valve so you can return it to the same setting.
- 4
Drain the radiator
~0.25 daysHold a bucket under the lower union, loosen the nut slowly with a spanner, and open the bleed valve at the top to let air in. Drain until the water stops.
The water can be dirty and black. Keep everything covered.
- 5
Remove the old and fit the new radiator
~0.5 daysUndo the unions, lift the old radiator off its brackets, and move the valve tails across to the new one with fresh PTFE tape. Fit the new brackets, hang the radiator, and tighten the unions.
- 6
Refill and bleed
~0.25 daysOpen the valves, let the radiator fill, and bleed air out through the top valve until water flows. Check the boiler pressure and top up to the recommended level, usually 1–1.5 bar.
- 7
Add inhibitor and check for leaks
~0.25 daysAdd inhibitor to the system to protect against corrosion, restore the lockshield setting, turn the heating on and check every joint is dry.
Learn from others
Common mistakes to avoid
- Buying a radiator with different pipe centres, which then needs new pipework
- Forgetting to close both valves before draining
- Not noting the lockshield setting, so the system is out of balance
- Leaving the boiler pressure too low after refilling
- Skipping inhibitor, which leads to sludge and corrosion
Frequently asked questions
How much does it cost to replace a radiator?
For two mid-range panel radiators with new valves, swapped like for like, expect from around £330 doing it yourself (materials only) to £720 with a plumber. Designer radiators and a power flush cost more.
How much does a radiator cost?
A mid-range double-panel radiator costs around £130. Budget panels are cheaper, and designer, vertical or high-output radiators cost several times more.
Can I replace a radiator myself?
A like-for-like swap on a standard heating system is a reasonable DIY job if you are comfortable draining and refilling the system. It is not notifiable work and does not involve the boiler. Anything involving the boiler, gas pipework or moving radiators needs a qualified plumber or Gas Safe engineer.
Why is my radiator not heating up?
The most common cause is trapped air. Bleeding the radiator with a radiator key, until water spits out, often fixes it. If it is cold at the bottom and warm at the top, it may be sludge, and the system may need a power flush.
What size radiator do I need?
It depends on the room size, insulation and windows. Output is measured in watts or BTU, and an online BTU calculator or your plumber will size it. Swapping like for like in the same room keeps the output similar.
Ready to plan it?
Add this job to your renovation plan to get the order of work, who to book and a budget you can track.