Boiler Installation Cost London 2026
Transparent pricing on new boiler installation across London — combi, system, and heat-only. Worcester Bosch Accredited Installers. Fixed quotes, no surprises, completed in a day.
Which Boiler Type Does Your London Home Need?
The most important decision is the boiler type. Getting this wrong costs thousands — either in performance problems or in unnecessary conversion work. Here's how each type fits London housing:
Combi BoilerMost Popular
Heats water on demand — no cylinder or cold water tank needed. Best for London flats and smaller terraced houses with 1–2 bathrooms.
✓ Space-saving (no tank/cylinder) ✓ Hot water instantly ✓ Lower installation cost
✗ Struggles with simultaneous use in large homes ✗ Flow rate limited by boiler output
£1,800–£3,000
Warranty: Up to 10 years
System Boiler
Works with a hot water cylinder. Handles multiple bathrooms simultaneously. Suits larger London homes with 3+ bedrooms.
✓ Multiple bathrooms at once ✓ Mains pressure hot water ✓ Compatible with solar thermal
✗ Cylinder takes up space ✗ Hot water can run out
£2,200–£3,800
Warranty: Up to 10 years
Heat-Only (Regular) Boiler
Traditional boiler with separate cold water tank in the loft and hot water cylinder. Common in older London homes with gravity-fed systems.
✓ Simple, proven technology ✓ Compatible with older radiator systems ✓ High flow rate potential
✗ Most space-consuming ✗ Cold water tank in loft ✗ Gravity pressure unless pumped
£2,000–£3,500
Warranty: Up to 10 years
New Boiler Installation Prices — London 2026
| Installation Scenario | Time | Total Price (supply & fit) |
|---|---|---|
| Like-for-like combi replacement (mid-range brand) | 1 day | £1,800–£2,400 |
| Like-for-like combi (Worcester Bosch / Vaillant) | 1 day | £2,200–£3,000 |
| System boiler replacement | 1 day | £2,200–£3,800 |
| Heat-only boiler replacement | 1 day | £2,000–£3,500 |
| Back boiler to combi conversion | 1–2 days | £2,800–£4,500 |
| Boiler relocation (same type, new position) | 1–2 days | £2,500–£4,000 |
| Magnetic filter (add-on, recommended) | Included | +£150–£200 |
| Smart thermostat (Nest / Hive / Honeywell) | 30 min | +£150–£300 |
Prices vary by property, boiler output required (kW), and any additional pipework. We survey before quoting — no obligation.
Boiler Brands We Install
We install all major brands and are Worcester Bosch Accredited Installers — which means we can offer the full 10-year warranty that standard Gas Safe engineers cannot. Here's how the brands compare for London conditions:
| Brand | Reliability | Warranty | Best for |
|---|---|---|---|
| Worcester Bosch | ★★★★★ | Up to 10yr | Most London home types — our #1 recommendation |
| Vaillant | ★★★★★ | 5–10yr | High efficiency, modern London homes |
| Viessmann | ★★★★★ | 5–7yr | Premium builds, maximising efficiency |
| Baxi | ★★★★☆ | 7–10yr | Great value — mid-range budget |
| Ideal | ★★★★☆ | 7–10yr | UK-made, good parts availability |
| Glow-worm | ★★★☆☆ | 2–5yr | Budget installs only |
What's Included in Our Installation Price
Every boiler installation we quote includes the following as standard. We never price low and add extras on the day.
| Item | Included? |
|---|---|
| New boiler unit (brand and model as quoted) | ✅ Yes |
| Gas Safe registered installation | ✅ Yes |
| Standard flue (horizontal through external wall, up to 1m) | ✅ Yes |
| Gas pipe connection / conversion fitting | ✅ Yes |
| Central heating inhibitor dose | ✅ Yes |
| System flush before installation | ✅ Yes |
| Boiler commissioning and test | ✅ Yes |
| Building Regulations notification (Part L) | ✅ Yes |
| Manufacturer warranty registration | ✅ Yes |
| Gas Safe certificate | ✅ Yes |
| Magnetic filter (Fernox TF1 or similar) | Quoted separately (+£150) |
| Smart thermostat | Quoted separately (+£150–£300) |
| Extended flue run (over 1m) | Quoted separately |
| Additional pipework or radiators | Quoted separately |
Boiler Installation Across All London Boroughs
We install boilers in every London borough — from Barnet to Bromley, Ealing to Greenwich. Survey visits available within 24 hours. Most installations completed within 3–5 working days of quote acceptance.
Boiler Installation FAQs
How much does a new boiler cost in London in 2026?
A new combi boiler fully fitted in London costs £1,800–£3,500 depending on the boiler brand and any pipework changes needed. Like-for-like combi replacements start at £1,800 (mid-range brand, simple swap). A Worcester Bosch or Vaillant combi fully fitted typically costs £2,200–£3,000. System boiler replacements cost £2,200–£3,800. Conversions from back boiler or heat-only to combi cost £2,500–£4,500.
Which boiler brand is best for London homes?
Worcester Bosch and Vaillant are the most reliable in our experience with London's hard water conditions. Both offer 10-year warranties (Worcester Bosch when installed by an Accredited Installer). Baxi and Ideal are solid mid-range options with good parts availability. We recommend Worcester Bosch Greenstar or Vaillant ecoTEC for most London properties.
How long does boiler installation take?
A like-for-like boiler replacement (same position, same type) takes 4–6 hours and is typically complete in one day. A boiler conversion — moving the boiler, changing the system type, or removing a back boiler — takes 1–2 days. We leave you with hot water and heating the same day in nearly all cases.
Do I need a combi or system boiler for my London home?
Combi boilers are ideal for most London flats and smaller terraced houses with 1–2 bathrooms. They heat water on demand with no tank or cylinder. System boilers suit larger homes with 3+ bedrooms and multiple bathrooms where simultaneous hot water demand is high — they work with a hot water cylinder. We'll survey your property and recommend the right type before quoting.
Is a 10-year warranty included?
Worcester Bosch offers a 10-year warranty when installed by an Accredited Installer — we are accredited. Vaillant offers 5–10 years depending on the model. Baxi offers 7–10 years. The warranty is manufacturer-backed and covers parts and labour for boiler faults. Annual servicing is required to maintain the warranty.
What's included in the installation price?
Our quoted price includes: the boiler unit, Gas Safe installation by a registered engineer, flue (standard horizontal through external wall), gas pipe connection, system flush, commissioning, Building Regulations notification (Part L), and manufacturer warranty registration. Magnetic filter, smart thermostat, and extended pipework are quoted separately if needed.
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