London Heroes — home

Boiler installation in London

Replacing a gas boiler is gas work: anyone fitting one must be competent, and any engineer you pay to fit it must be on the Gas Safe Register. Ask for a price that covers the whole job, from the boiler and the flue to the controls and making good. You see the full price before you pay, and nothing is added to it unless you approve.

If you smell gas, or a carbon monoxide alarm sounds: don't smoke, light a flame or touch light switches, open the doors and windows, turn the gas off at the meter if you can reach it safely and it isn't in a cellar or basement, get everyone out, and call the National Gas Emergency Service free on 0800 111 999 before anything else — before calling us.

Request a verified professionalTypical UK price, like-for-like combi swap: £2,150–£4,000 per installation

Sound familiar?

  • An engineer has advised replacing the boiler rather than repairing it
  • Parts for the boiler's model are hard to find
  • You want to change from a system or regular boiler to a combi
  • You want the boiler moved to another room
  • You have an old back boiler behind a fire

What your Hero will do

  1. 1Check the existing system, from the radiators and pipework to the flue route, gas supply and water pressure, so the new boiler suits the home
  2. 2Remove the old boiler and fit the new one, flushing the system and fitting a filter where the pipework needs it
  3. 3Commission the boiler and run it through a full heating and hot water cycle, checking the safety devices
  4. 4Go through the new boiler's paperwork with you, and tell you how the installation will be notified under the Building Regulations, so that its compliance certificate reaches you
  5. 5Record the installation on your job's timeline for future reference

When to call

Not sure whether an older boiler is worth repairing? The boiler repair cost guide answers it.

Before the old boiler gives out, if you can: replacing one that still works lets you choose the boiler and the date, rather than deciding on the day it stops. If you smell gas, or a carbon monoxide alarm sounds: don't smoke, light a flame or touch light switches, open the doors and windows, turn the gas off at the meter if you can reach it safely and it isn't in a cellar or basement, get everyone out, and call the National Gas Emergency Service free on 0800 111 999 before anything else — before calling us.

Common questions

Can you legally install your own boiler?
Only if you are competent to do gas work. Regulation 3 of the Gas Safety (Installation and Use) Regulations 1998 says no one may carry out work on a gas fitting unless they are competent to do so, and any business or self-employed engineer doing gas work must be on the Gas Safe Register. Those rules apply in a home you own as much as in one you let. Fitting a new boiler is also notifiable work under the Building Regulations, so if a Gas Safe registered business does not fit it, local authority building control must be notified and must inspect it. HSE strongly advises having gas appliances installed by a Gas Safe registered engineer, and any engineer you pay to fit a boiler must be registered.
What paperwork should I get after a new boiler is fitted?
A Building Regulations compliance certificate. Fitting a new boiler is notifiable gas work, and the certificate confirms the work meets Building Regulations. When a Gas Safe registered business fits a gas boiler, Gas Safe Register issues the certificate, and it can provide a replacement copy if yours is lost; where local authority building control inspected the work instead, the certificate comes from building control. It is a different document from a landlord's annual gas safety record.

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