Welcome to OnTimePlumbers
New Boiler Installation In London
Need a new boiler fitted? OnTime Plumbers installs and replaces combi, system and conventional boilers across London, Hertfordshire, Essex and Surrey. Every installation is carried out by a Gas Safe registered, City & Guilds qualified engineer, with a fixed price agreed before any work starts.
Whether your current boiler has broken down, is losing pressure, or is simply too old to run efficiently, we’ll help you choose the right replacement and get it fitted — usually within the same week.
Gas Safe Registered (ID 638777) · City & Guilds Qualified · 5.0 Google Reviews · London, Herts, Essex & Surrey
When Do You Need a New Boiler?
A boiler doesn’t need to have broken down completely before it’s worth replacing. The clearest signs it’s time for a new installation:
- Age — most gas boilers last 10–15 years; efficiency drops noticeably after that
- Rising gas bills with no change in usage
- Frequent breakdowns or repeated call-outs for the same fault
- Uneven heating, cold radiators, or a boiler that keeps losing pressure
- Strange noises — banging, whistling or kettling from the unit
- No longer A-rated — older G/F/E-rated boilers waste significantly more gas than a modern condensing boiler
- No parts available — some older or discontinued models can no longer be repaired
If two or more of these apply, a replacement will usually cost less over time than continuing to repair the old unit.
Types of Boiler We Install
We install and replace all three main boiler types, and can advise which suits your property, hot water usage and budget during a free survey.
Combi Boilers Heats water on demand with no separate tank or cylinder — the most common choice for flats and smaller homes with one bathroom. Compact, and delivers hot water instantly.
System Boilers Works with a hot water cylinder but doesn’t need a cold water tank in the loft. A better fit for homes with more than one bathroom, where several taps or showers may run hot water at the same time.
Conventional (Regular) Boilers Uses both a hot water cylinder and a cold water feed tank. Common in older properties and larger homes with higher hot water demand, or where the existing pipework favours a like-for-like swap.
Switching boiler type? A back boiler or system-to-combi conversion takes longer and costs more than a like-for-like swap, as it involves removing tanks and reworking pipework. We’ll flag this — and the added cost — during your free survey, not after the job starts.
Boiler Installation Cost in London
Boiler installation costs vary by boiler type, property size and how much pipework is involved. As a guide for London in 2026:
| Job type | Typical installed price (London) |
|---|---|
| Like-for-like combi replacement | £2,000 – £3,000 |
| New combi (mid-range, standard fit) | £2,800 – £4,000 |
| System boiler installation | £3,000 – £5,000 |
| Conventional boiler replacement | £2,800 – £4,500 |
| Boiler type conversion (e.g. system to combi) | £4,000+ |
These figures include the boiler unit and labour for a standard installation. Your exact price depends on your boiler’s output requirement, existing pipework and flue position, and whether the boiler is moving location. We provide a fixed, written quote after a free survey — the price you’re quoted is the price you pay, with no hidden extras added on the day.
Boiler Brands We Install
We fit boilers from the manufacturers most commonly specified for London homes, including:
- Worcester Bosch
- Vaillant
- Ideal
- Baxi
- Glow-worm
All are A-rated for energy efficiency and come with manufacturer warranties of up to 10–12 years, provided the boiler is serviced annually.
Our Boiler Installation Process
1. Free Survey An engineer assesses your property, existing system, gas supply and hot water needs, and talks you through your boiler options.
2. Fixed Quote You receive a clear, written price covering the boiler, labour and any additional parts — agreed before work begins.
3. Installation Day Your Gas Safe registered engineer removes the old boiler, fits the new unit, and connects it to your heating and hot water system. Most straightforward like-for-like installations are completed in a single day.
4. Testing & Handover The system is pressure-tested, commissioned, and you’re shown how to use your new controls and thermostat before we leave.
Why Choose OnTime Plumbers for Your Boiler Installation
- Gas Safe Registered (ID 638777) — every engineer is legally certified to work on gas boilers
- City & Guilds Qualified engineers
- Fixed pricing — no surprise costs on installation day
- 5.0 Google Reviews
- Cover across London, Hertfordshire, Essex and Surrey
- Support beyond installation — emergency plumbing and drainage services if you ever need them
Areas We Cover
We install boilers across all London boroughs, plus Hertfordshire, Essex and Surrey, including Camden, Islington, Hackney, Wandsworth, Croydon, Ealing, Greenwich, Barnet and surrounding areas.
Boiler Installation FAQs
Do I need a new boiler, or can it be repaired?
If your boiler is over 10–15 years old, breaks down repeatedly, or is no longer A-rated, replacement is usually more cost-effective than ongoing repairs. A free survey will confirm which makes sense for your system.
How long does a boiler installation take?
A standard like-for-like combi replacement is usually completed in a single day (4–8 hours). Installations involving a boiler type change, relocation, or pipework upgrades can take 2–3 days.
How much does a new boiler cost in London?
Most London homeowners pay between £2,000 and £4,000 for a fully installed combi boiler, and £3,000 to £5,000 for a system boiler. Exact pricing depends on your property, boiler output and installation complexity — we confirm this with a fixed quote after a free survey.
Do you install combi, system and conventional boilers?
Yes. We install and replace all three boiler types, and our engineers will recommend the right one for your property size, number of bathrooms and hot water demand during your survey.
Are your engineers Gas Safe registered?
Yes. All engineers are Gas Safe registered (ID 638777) and City & Guilds qualified. It’s illegal for anyone who isn’t Gas Safe registered to install or work on a gas boiler in the UK.
What boiler brands do you fit? We install Worcester Bosch, Vaillant, Ideal, Baxi and Glow-worm boilers — all A-rated for energy efficiency.
Do you offer a warranty on new boiler installations?
Manufacturer warranties on the boilers we install run up to 10–12 years, provided the boiler is serviced annually. [Confirm exact workmanship guarantee terms before publishing — not stated on current site.]
Can I get emergency boiler installation?
If your boiler has broken down completely and you need a replacement urgently, call our 24/7 line on 08000 584799 and we’ll assess how quickly we can survey and install.