2026 price bands (supplied & fitted)
These are honest ranges from jobs we quote every week across the BA and BS postcodes. Prices include a system flush, magnetic filter and manufacturer warranty registration.
| Install type | Typical 2026 price | What's included |
|---|---|---|
| Combi swap (like-for-like) | £2,100 – £2,800 | Same wall, existing pipework flushed and reused |
| Combi swap + pipework upgrade | £2,500 – £3,400 | Gas run upsize, magnetic filter, new controls |
| System boiler replacement | £2,700 – £3,700 | Keeps cylinder — good for 3+ bathrooms |
| System-to-combi conversion | £3,200 – £4,600 | Remove cylinder + tanks, cap feeds, full flush |
| Oil boiler (internal) | £3,400 – £4,600 | Worcester Greenstar Heatslave / Grant Vortex |
| Oil boiler (external) + tank | £4,200 – £6,000 | Bunded tank + base + fuel-line renewal |
What actually moves the price?
- Brand & warranty tierWorcester Bosch 10-yr vs Ideal 7-yr adds £150–£350.
- Output (kW)24kW vs 30kW combi ≈ £120 more, but often needed for 2 bathrooms.
- Gas pipeworkOld 15mm runs often need upsizing to 22mm — £180–£400.
- Flue routeVertical flue kit or plume management: £160–£380.
- System conditionSludgy old radiators may need a power flush: £320–£520.
- Smart controlsNest / Hive / Wave thermostat + fitting: £180–£300.
- AccessLoft or awkward cupboard installs add labour.
- RemovalsCylinders, cold tanks and old flues taken away and recycled.
How prices differ by area
Bath (BA1–BA2)
Georgian and listed stock; conservation-area flue routing sometimes needs a plume kit or vertical flue. Add £200–£600 vs a standard swap.
Radstock & Midsomer Norton (BA3)
Mostly 1950s–1980s semis and detached — usually a clean swap with an easy gas run. Prices at the lower end of each band.
Wells & Shepton Mallet (BA4–BA5)
Mix of stone cottages and rural properties. Combi upgrades from old regular systems are the most common job.
Chew Valley (BS39–BS40)
Lots of off-grid homes — oil is common. LPG and heat-pump quotes available for hybrid setups.
Frome & surrounding villages
Older stone properties often need pipe upsizing and a scale reducer on hard-water combi installs.
What we include as standard
- Free home survey and fixed written quote
- System power-flush or chemical clean as required
- Magnetic system filter (Adey / Fernox)
- Manufacturer warranty registration (up to 10 yrs)
- Gas Safe / OFTEC benchmark and building-notice paperwork
- Removal & recycling of old boiler, cylinder and tanks
Related reading
Get a fixed written quote for your home
Free survey across Bath, Radstock, Wells, Midsomer Norton and the Chew Valley. Same-week appointments most of the year.