Like-for-like radiator swaps and new radiator circuits
Radiator Installation and Replacement
Radiator installation covers replacing an existing radiator like-for-like, upgrading to a higher-output or designer radiator, or adding a new radiator on an extended heating circuit, connected to the existing central heating system.
Definition
What Radiators covers
A radiator replacement swaps an old or corroded radiator for a new one on the existing pipework and valves, while a new installation extends the heating circuit to a room that didn't previously have one — for example following a loft conversion or extension. Correct sizing matters: an undersized radiator will struggle to heat the room even on a well-performing boiler.
Suitable for
- Old, corroded or leaking radiators needing replacement
- Upgrading to a higher-output or designer radiator
- Adding a radiator to a room with no existing heating, such as a converted loft
- Balancing a system where some rooms are consistently colder than others
Not suitable for
- Rooms where the underlying heating circuit needs significant extension or rebalancing — this is scoped and quoted once seen, not assumed within a simple swap price
- Radiators on a system with unresolved sludge or corrosion issues, where a power flush may be needed first
Process
How the work is carried out
- 01
Assessment
Checking the existing pipework, valves and whether the new radiator is correctly sized for the room.
- 02
Removal
Draining the relevant section of the system and removing the old radiator.
- 03
Installation
Fitting and connecting the new radiator, extending pipework where a new circuit is needed.
- 04
Testing
Refilling, bleeding and balancing the system, and checking for leaks.
Typical timescale
A single like-for-like radiator swap is typically completed within a few hours; a new radiator on an extended circuit can take longer depending on pipe run and floor access. Multiple radiators are usually completed within a day.
Cost guidance
Radiator installation typically costs £150–£350 per radiator in our area, with a like-for-like swap toward the lower end and a new circuit or floor-lifting work pushing costs higher. We provide an itemised quotation after assessment rather than a fixed headline price.
Limitations and exclusions
- New radiator circuits that require lifting floors or chasing walls are priced once the pipe route is confirmed on site
- Radiator valves and thermostatic radiator valves (TRVs) are included as standard unless a specific type is requested
- Pre-existing system issues such as sludge or corrosion, if found, are flagged and quoted separately
Areas we cover
Radiators across Sussex, Surrey, Kent and South London
Local property styles, planning authorities and neighbourhood coverage for radiators in each town we work in.
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FAQs
Radiators FAQs
Can you match my existing radiators?
Yes, where a reasonably close match is available for the type and finish. We can also discuss upgrading to a higher-output or designer radiator if you're open to a different style.
Why has one room always been colder than the rest?
Common causes include an undersized radiator, a system that needs balancing, or a wider circuit design issue. We assess the specific cause on visit rather than guessing over the phone.
Do I need to drain the whole heating system for one radiator?
No, most radiator swaps only need the relevant section isolated at the valves. A full system drain is only needed for wider works, such as some new circuit installations.
Discuss your radiators project
Tell us about the property and what you have in mind, and we'll arrange a site visit.
Last reviewed 2026-07-28.