What is Rare Plumbing Website?

A bespoke digital atelier providing precision engineering and climate control services for London's most discerning luxury estates.

Why do boiler brands vary so much in price?

Premium brands like Viessmann and ATAG use higher-grade components, achieve greater efficiency and typically carry longer warranties — which is reflected in the purchase price. Ideal and Worcester Bosch offer excellent value at a lower price point.

Are there any government grants available?

Depending on your circumstances, you may be eligible for the Boiler Upgrade Scheme (BUS) or ECO4 grant, which can contribute towards a new boiler or heat pump. We can advise on eligibility during your survey.

What's included in the installation price?

Our quotes include the boiler, removal and disposal of your old unit, a system flush, magnetic filter, Gas Safe certification and warranty registration — no hidden extras.

How long does installation take?

A like-for-like combi replacement typically takes one day. Switching boiler types or adding a cylinder can take 1–2 days depending on the property.

Do you offer financing or payment plans?

Yes — ask our team about available payment plan options when you receive your fixed quote.

How much does a new boiler cost in London?

A new combi boiler installation in London costs £3,200–£4,200 including the boiler, system flush, magnetic filter, Gas Safe certification and smart thermostat. A system boiler with an unvented cylinder costs £4,800–£6,000. Premium brands like Viessmann and ATAG add £600–£1,100 to the baseline.

Is a system boiler more expensive to install than a combi?

Yes — a system boiler installation costs £1,600–£1,800 more than a combi because it requires a hot water cylinder, additional pipework and a longer installation time. However, a system boiler delivers mains-pressure hot water to multiple bathrooms simultaneously, which a combi cannot do.

What is the cheapest boiler installation in London?

The most cost-effective boiler installation is a like-for-like combi replacement using a mid-range brand such as Ideal or Worcester Bosch, typically £3,200–£3,600. We do not recommend economy brands for London properties — the reliability and warranty differences are not worth the small saving.

Does a new boiler add value to a London property?

A new A-rated boiler with a valid warranty can improve a property's EPC rating and is a positive selling point for prospective buyers. While the installation cost is not fully recovered in property value, a new boiler removes a common buyer objection and can speed up a sale.

Can I spread the cost of a new boiler?

Yes — we offer payment plan options that allow you to spread the cost of a new boiler over monthly instalments. Ask our team about available plans when you receive your fixed quote.

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Boiler Repairs Plumbing Underfloor Heating Central Heating Combi Boiler Install Power Flushing Smart Thermostats Air Conditioning PPM Maintenance

Transparent Pricing

Boiler Installation Costs London

Combi, system & conventional boiler pricing. Premium brands. Fixed quotes within 2 hours. No hidden charges, no surprises.

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Available 24/7. Gas Safe registered engineers.

A combi boiler installation in London costs £3,200–£4,200 including the boiler, system flush, magnetic filter, Gas Safe certification and smart thermostat. System boilers with a cylinder cost £4,800–£6,000. Premium brands like Viessmann and ATAG cost more but offer longer warranties and higher efficiency. All quotes are fixed price after a survey.

Quick Facts

Combi boiler: £3,200–£4,200 inc. installation, flush, filter and certification
System boiler: £4,800–£6,000 inc. cylinder and commissioning
Premium brands: Viessmann, ATAG, Vaillant — longer warranties, higher efficiency
What is included: Boiler, installation, system flush, magnetic filter, Gas Safe cert
Quote type: Fixed price after survey — no hidden extras
Installation time: 1 day for like-for-like combi replacement

2026 Boiler Installation Price Guide

Combi Boiler

No cylinder, instant hot water

£3,200–£4,200

Supply & installation
System flush & magnetic filter
Gas Safety certificate
Smart thermostat included

System Boiler

With hot water cylinder

£4,800–£6,000

Supply & installation
Cylinder supply & fit
Power flush pre-install
Full commissioning

Conventional Boiler

Traditional gravity system

£4,200–£5,400

Supply & installation
Tank & cylinder install
System upgrade included
Building Regs approval

Brand Premium Pricing

Premium European brands command higher pricing due to efficiency, warranty & longevity:

Vaillant

+£600

Viessmann

+£900

ATAG

+£1,100

Worcester Bosch

+£400

Ideal

+£0 (baseline)

Optional Add-ons

System power flush

£650

Magnetic filter (Fernox TF1)

£220

Smart thermostat (Heatmiser/Tado)

£380

New flue route/extension

£480

Gas Safety Certificate (CP12)

£150

Building Regulations sign-off

£200–£400

Why Choose RARE for Your Boiler Installation

Premium Brands

Vaillant, Viessmann, ATAG, Worcester Bosch, Ideal and Keston.

Gas Safe Certified

All engineers fully registered. Full compliance documentation.

Workmanship Guarantee

12-month workmanship guarantee plus 5–10 year manufacturer warranty.

Transparent Pricing

Fixed quote in writing. No hidden charges or surprises.

Get Your Fixed Quote Today

Use our boiler calculator to get an indicative price, then request a fixed quote from our engineers. Response within 2 hours.

Use Calculator Call 020 7458 4949

Boiler installation — complete topic guide

Combi Boiler Installation

For flats & smaller homes

System Boiler Installation

For larger homes & plant rooms

Hot Water Cylinder Installation

Megaflo, OSO & unvented cylinders

Boiler Replacement Guide

Repair vs replace explained

Combi vs System Boiler

Which type is right for your home?

Vaillant vs Viessmann

Brand comparison

Boiler Repairs

24/7 emergency & planned repairs

Boiler Servicing

Annual Gas Safe service

Get a Boiler Quote

Fixed price in 3 steps

Heat Loss Calculator

Size your boiler correctly

FAQ

Installation Cost Questions

Still have questions?