Cost of installing a new boiler in London
Labour, what’s included, and what actually changes the price
If you’re searching “cost of installing a new boiler” or “how much is new boiler instalment”, you’re usually trying to separate the price of the boiler from the price of the work. This page focuses on the work: labour, compliance, system preparation, and the extras that quietly push quotes up.
We install boilers across London weekly. The most common issue we see isn’t the boiler itself — it’s poor installation assumptions. So below is the straight breakdown of what you’re paying for when you pay for installation.
In London, installation labour for a typical boiler job is often £1,000–£2,000. Straight swaps are cheaper. Relocations, conversions, access constraints and system issues push it up.
Typical boiler installation costs (labour) — real London scenarios
These are realistic labour ranges for the work itself. If you’re looking for the full all-in number (boiler + labour), use our broader guide on boiler cost and installation. This page stays focused on installation.
| Installation scenario | Typical labour cost (London) | What’s happening |
|---|---|---|
| Like-for-like swap (same type, same location) | £1,000 – £1,400 | Remove old, fit new, commission, paperwork (minimal pipe/flue changes) |
| Combi swap with system cleaning needed | £1,300 – £1,900 | Add cleaning/flush time, protection, balancing |
| Boiler relocation | £1,500 – £2,200 | New pipe runs, flue route changes, condensate routing, making-good |
| Conversion (e.g., regular/system → combi) | £1,800 – £2,600 | More changes: cylinder/tanks removed, pipework altered, controls adjusted |
| Flat install with tricky access / flue constraints | £1,600 – £2,400 | Access restrictions, routing limitations, compliance considerations |
Important: The keywords people mix together (like new combi boiler installation cost or cost of boiler replacement) usually include both the boiler price and the labour. On this page, we’re isolating the installation element so you can compare quotes properly.
What boiler installation should include (the stuff that protects you)
A quote can look “cheap” if it quietly removes the steps that keep your boiler safe, efficient, and warranty-friendly. Proper installation is not just mounting a box on a wall — it’s making sure the system around it won’t wreck it.
Installation usually covers
- Removal and safe disposal of the old boiler (and kit if required)
- Gas pipe sizing and pressure checks (and upgrades where needed)
- Flue positioning and compliance checks (especially important in flats)
- Condensate routing setup (and protection where freezing is a risk)
- Commissioning, safety checks, controls setup and handover
- Benchmark / documentation and warranty registration where applicable
Ready to book an install? Here’s the service page (kept service-led, not a pricing article): boiler installation in London.
What pushes the installation price up (and why it’s common in London)
When you see big differences between quotes, it’s usually these factors — not “one company being honest and one being a rip-off”. London properties have patterns: tight cupboards, awkward flue routes, old pipework, and systems that haven’t been cleaned in years.
Common cost drivers
- Relocation: moving the boiler means new pipe runs + flue routing changes
- System condition: sludge, blocked rads, noisy pumps — cleaning/protection adds time
- Conversions: switching types changes more than people expect
- Access constraints: flats, parking, stairs, restricted work areas
- Gas supply upgrades: modern boilers often need better feed than older installs
Send photos of the boiler, the pipework underneath, and where the flue exits. We’ll tell you if it looks like a straight swap or a “needs extra work” installation.
Common installation extras (not always needed — but often included)
These items are often discussed alongside “cost of installing new boiler” because they sit in the middle: not the boiler itself, but not pure labour either. They’re the protective pieces and system work that reduce breakdown risk.
| Extra | Typical cost range | What it’s for |
|---|---|---|
| System flush / cleaning | £400 – £1,000 | Removes sludge/debris that can damage the new boiler |
| Magnetic filter | £100 – £300 | Catches magnetite and reduces future faults |
| Smart thermostat | £150 – £300 | Better control and efficiency if used properly |
| Radiator balancing / minor remedial work | £150 – £450 | Improves heat distribution and reduces strain |
If you’re comparing cost of boiler replacement quotes, check whether these are included, excluded, or assumed unnecessary. That’s where “cheap” installs often become expensive later.
Related guides (if you’re comparing the bigger decision)
Installation cost is only one part of the total. If you’re researching the full decision, these pages cover the other intent buckets:
- boiler cost and installation (all-in costs)
- book a boiler installation in London
- repair vs replace (when a fix is smarter)
- keep a boiler healthy long-term
- emergency boiler help in London
- all gas appliance services
(6 internal links, all unique anchors — clean and controlled.)
FAQ — installation costs (quick answers)
How much does it cost to install a new boiler (without the boiler price)?
In London, installation labour commonly lands around £1,000–£2,000 depending on whether it’s a straight swap, relocation, conversion, access constraints, and system condition.
Does “new combi boiler installation cost” include the boiler?
Most of the time yes — people use that phrase to mean the all-in price (boiler + labour). If you want to compare properly, ask quotes to separate the boiler supply cost from installation labour and system extras.
How long does a boiler installation take?
Many like-for-like swaps can be done in a day. Relocations, conversions and jobs involving cleaning or significant pipe/flue changes can take longer. A quick photo review usually tells you which category you’re in.
Do I always need a power flush for a new boiler installation?
Not automatically. If the system is dirty, cleaning helps protect the new boiler and reduce breakdown risk. If the system is clean and well maintained, it may not be necessary.
Is replacement cost the same as installation cost?
Not exactly. “Cost to replace a boiler” usually means the full project cost (boiler + installation + any system work). This page isolates installation so you can understand the labour side clearly.