Heating Engineer Cost UK 2026: Service, Repair, Install
Heating engineer costs in the UK, 2026
Heating engineer pricing covers boiler servicing, repairs, replacements, full system installs, and increasingly heat pump and renewable system work. Gas Safe registration is a legal requirement for any gas work — never use an unregistered engineer for boilers or gas systems.
This guide covers typical 2026 UK heating engineer prices, plus what's included in different service types.
Typical UK heating engineer costs (2026)
| Job | Typical UK 2026 price | Notes |
|---|---|---|
| Annual boiler service | £90–£130 | Required to maintain manufacturer warranty. |
| Boiler diagnostic callout | £75–£150 | Usually deducted from repair cost. |
| Common boiler repairs (PCB, fan, ignition) | £180–£480 | Includes parts and labour. |
| Replace combi boiler (like-for-like) | £1,800–£3,200 | 1 day. Premium brands at higher end. |
| Replace combi boiler with system or regular boiler | £2,500–£4,800 | 2 days. Includes pipework reconfiguration. |
| Install unvented hot water cylinder | £1,800–£3,200 | Includes Building Regs notification. |
| Power flush (whole system) | £480–£850 | 1 day. Recommended every 5-10 years. |
| Smart thermostat install (Hive, Nest, etc.) | £180–£320 | Inc. boiler interface kit if needed. |
| Add 1 radiator to existing system | £220–£480 | Inc. valves, supply, fit. |
| Full central heating install (3-bed semi) | £5,500–£9,500 | 3-5 days. Includes boiler + 8-10 radiators. |
| Underfloor heating (wet, per sqm) | £90–£180 | Excludes screed and floor finish. |
| Air source heat pump install | £9,000–£14,000 | BUS grant deducts £7,500. See heat pump cost guide. |
What changes the cost
- Boiler brand and warranty: Worcester Bosch, Vaillant, and Viessmann command premium pricing but offer 7-10 year warranties. Budget brands (Ideal, Baxi) are 20-30% cheaper but typically have 5-7 year warranties.
- System change vs like-for-like: swapping a combi for a combi is fastest. Switching system type (combi to system, or removing a hot water cylinder) requires pipework reconfiguration and adds 1-2 days.
- Building Regulations notification: any new boiler install must be notified to Building Control, which a Gas Safe engineer handles via their competent-person scheme. Unregistered engineers can't do this and you'd pay separately for Building Control approval.
- Power flush: a flush is mandatory if you're replacing a boiler on an old system — sludge from the old system damages the new boiler within months. Often presented as optional but it's not.
- Smart controls: adding a Hive, Nest, or tado smart thermostat to a new boiler install adds £180–£320 but pays back through 15-25% reduced gas use.
How to vet a heating engineer
Always check Gas Safe registration on site — ask for the card and verify the number at GasSafeRegister.co.uk. The card lists which appliance categories the engineer is qualified for. A Gas Safe engineer for boilers is not necessarily qualified for LPG or commercial systems.
For finding a heating engineer in Kent, see our how to choose a heating engineer guide. For boiler-specific costs, see new boiler cost UK 2026.
Frequently asked questions
How much is an annual boiler service?
£90-£130 in 2026. Required to maintain manufacturer warranties on most boilers (typically 7-10 years on Worcester or Vaillant). A full strip-down service should take 60-90 minutes; anything faster is likely just a visual inspection.
How much does a new boiler cost installed?
Like-for-like combi replacement runs £1,800-£3,200 in 2026. Switching system type (combi to system or vice versa) runs £2,500-£4,800 due to pipework changes. Premium brands (Worcester, Vaillant) sit at the higher end.
Do I need a power flush with a new boiler?
On an old system (10+ years), yes — sludge from the old system will damage the new boiler within months. On a relatively new system in good condition, it's optional. Reputable engineers will assess and recommend honestly.
Can I add a radiator to my system?
Yes, most systems can take 1-2 additional radiators without upgrading the boiler. Cost typically £220-£480 inc. valves, supply, and fit. Larger additions or whole-house extensions may require boiler upsizing.