New boiler installationin Harrow, fitted rightand covered for up to 10 years
A new Worcester Bosch or Vaillant boiler, sized to your home and installed by a Gas Safe registered approved installer, with manufacturer warranties of up to 10 years.
Approved installer for Worcester Bosch & Vaillant · 20 years' experience
20 years
trade experience
Gas Safe
Registered no. 961481
£10m
public liability cover
24/7
emergency service
10 years
copper pipework guarantee
Service overview
Boiler Installation: what it is and when you need it
What it is
A boiler installation is the removal of your old boiler and the fitting of a new, efficient gas boiler, along with the flue, controls, gas supply and connections to your heating and hot water system. Done properly, it is a 10 to 15-year decision about how warm your home is and how much you spend on gas.
Who it's for
It is for homeowners whose boiler is old, unreliable or inefficient, landlords replacing a boiler in a let property, and anyone renovating, extending or changing from one type of system to another, such as a conventional system to a combi.
When you need it
Most people replace a boiler when repairs start to cost more than the boiler is worth, when parts are no longer available, when the boiler keeps breaking down in winter, or when energy bills creep up because the old unit is far less efficient than a modern condensing boiler.
Why use a professional
A boiler that is the wrong size, badly positioned or poorly commissioned will waste gas, short-cycle and fail early, and manufacturer warranties depend on the boiler being fitted and registered correctly. As approved installers for Worcester Bosch and Vaillant, we can offer manufacturer warranties of up to 10 years on new boilers, and our copper pipework carries a 10-year guarantee.
The cost of waiting
What happens if you leave it
Putting off a replacement rarely saves money. An ageing boiler usually costs more each year it stays on the wall.
Risks if it's ignored
- Repeated call-out and repair bills on a boiler that will still need replacing.
- Higher gas bills, because older non-condensing boilers waste far more heat up the flue.
- Breakdowns that tend to happen in the coldest weeks, when the boiler works hardest.
- Obsolete parts, leaving you without heating or hot water while you wait for a new boiler anyway.
Common mistakes we see
- Choosing a boiler on price alone instead of the right output for the home.
- Fitting a new boiler onto a dirty system without addressing sludge, which shortens its life.
- Not registering the warranty, or using an installer who cannot offer the extended manufacturer warranty.
- Accepting a quote without a survey of the home, flue route and gas supply.
Our process
How we handle your boiler installation
01
Survey
We look at your home, hot water use, existing system, flue route and gas supply before recommending anything.
02
Clear quote
You get a bespoke written price for the right Worcester Bosch or Vaillant boiler. Installs over £2,000 usually need a 50% deposit.
03
Installation
We remove the old boiler and fit the new one, flue, controls and pipework, keeping disruption to a minimum.
04
Testing & commissioning
We test the gas, flue and system, set up the controls and make sure heating and hot water work as they should.
05
Handover & warranty
We show you how to use the boiler, register the warranty, and commit to fixing any installation issue until you're fully satisfied.
What you get
The benefits of doing it properly
Lower running costs
A modern condensing boiler sized to your home uses gas more efficiently than an old, oversized unit.
Up to 10-year warranty
Approved installer status means access to manufacturer warranties of up to 10 years.
Reliable winters
Fewer breakdowns and no more nursing an old boiler through cold spells.
Safe by design
Fitted and commissioned by a Gas Safe registered engineer (961481).
10-year pipework guarantee
Copper pipework we install is guaranteed for 10 years.
Clear price
A bespoke written quote after a survey, so you know the cost before work starts.
In detail
Choosing the right new boiler for your home
There is no single best boiler. The right choice depends on how many bathrooms you have, how much hot water you use at once, the space available and your existing pipework.
Price
Bespoke quote after survey
Combi boilers
A combination boiler heats water on demand straight from the mains, so there is no hot water cylinder or loft tank. Combis suit flats and most houses with one bathroom, freeing up cupboard space. Output needs to match your mains flow and how many taps run at once.
System boilers
A system boiler heats a sealed hot water cylinder. It suits homes with two or more bathrooms where several people need hot water at the same time, and works well alongside solar thermal or a future heat pump.
Regular (heat-only) boilers
Regular boilers work with a cylinder and cold water tanks in the loft. They suit older properties with existing gravity-fed systems where changing the layout would be costly or where water pressure is low.
Combi swaps and system conversions
Changing from a conventional system to a combi can free up space and remove the loft tank, but it is not always the right move for larger households. We explain the trade-offs honestly at survey.
Flues, condensate and positioning
Every boiler needs a safe flue route and a condensate pipe that will not freeze. We plan the position for safety, access for servicing and the shortest sensible pipe runs.
Protecting your new boiler
Fitting a new boiler onto old, sludged pipework is a common reason for early failures. Where needed we recommend a power flush and a magnetic filter so the new boiler starts on a clean system.
Landlords and let properties
For landlords, a reliable boiler means fewer emergency call-outs from tenants. We can combine the installation with your Landlord Gas Safety Certificate (CP12).
Useful guide
How long a boiler installation takes and what to expect on the day
A straightforward like-for-like boiler swap is usually completed in a day. Moving the boiler to a new position, converting from a regular system to a combi, or adding a new cylinder takes longer because pipework, the flue route and sometimes the gas supply need to change. We tell you the expected timeline at survey, so you can plan around hot water and heating being off.
On the day, we protect floors and work areas, drain the system, remove the old boiler and fit the new one. Once connected, we fill and test the system, check the gas and flue, set up the controls and walk you through how everything works before we leave.
Why J&L
Why homeowners and landlords call us
J&L Gas & Renewables Limited is a Gas Safe registered heating and gas engineering company based in Harrow, registration number 961481. We bring 20 years of trade experience to every job, from a single repair to a full heating system.
We are approved installers for Worcester Bosch and Vaillant, so new boilers can come with manufacturer warranties of up to 10 years. Copper pipework we install carries a 10-year guarantee, and we carry £10 million public liability cover.
Our pricing is clear: Landlord Gas Safety Certificates cost £75, boiler services start from £100, and a combined certificate and service starts from £150. Installations are quoted individually after a survey. If anything isn't right after an installation, we commit to putting it right until you're fully satisfied.
Local service
Boiler Installation across North West London and Hertfordshire
We're based at Banner House, 29 Byron Road, Harrow, and cover homes and rental properties in these areas:
- Harrow
- London
- Watford
- Stanmore
- Radlett
- St Albans
- Bushey
- Rickmansworth
- Hemel Hempstead
- Barnet
- Pinner
- Edgware
- Wembley
- Ruislip
- Northwood
- Borehamwood
- Mill Hill
- Kings Langley
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Questions
Boiler Installation FAQs
Can't see your question? Call 07843 900760; our emergency heating service runs 24/7.
How much does a new boiler cost in Harrow?
Every installation is priced individually after a survey, because the right boiler, flue and pipework vary from home to home. You get a written quote before any work begins.
Is a deposit required?
For boiler installations over £2,000 we usually take a 50% deposit, with the balance paid by bank transfer on invoice.
What warranty will I get?
As Worcester Bosch and Vaillant approved installers, we can offer manufacturer warranties of up to 10 years on new boilers. Copper pipework carries our 10-year guarantee.
Which brands do you install?
We are approved installers for Worcester Bosch and Vaillant.
What happens if something isn't right after installation?
We commit to rectifying any installation issue so you are fully satisfied.
How long does a new boiler installation take?
A like-for-like swap is usually a day. Relocations and system conversions take longer; we give you a timeline at survey.
How long does a new boiler last?
A well-installed, annually serviced boiler typically lasts many years. Annual servicing also keeps the manufacturer warranty valid.
Do you offer a 24/7 emergency service?
Yes. J&L Gas & Renewables runs a 24/7 emergency service for boiler breakdowns and heating faults across Harrow, North West London and Hertfordshire. Call us at any hour and speak to us directly.
Are your engineers Gas Safe registered and insured?
Yes. We are Gas Safe registered (number 961481) and carry £10 million public liability cover. You can check our registration on the Gas Safe Register before we arrive.
How do I pay?
Payment is by bank transfer on invoice. For boiler installations over £2,000 we usually ask for a 50% deposit. Payment timing is agreed with your quote.
Get your boiler installationsorted by a Gas Safe engineer.
1. You call or send the form
Tell us what you need, your postcode and the best time to reach you. Let us know whether you need an installation, servicing or emergency heating help.
2. You get a clear price
CP12 certificates cost £75, servicing starts from £100 and combined visits start from £150. For bigger jobs, a written quote after we've seen the work, so there are no surprises later.
3. We do the work properly
A Gas Safe registered engineer completes the job, tests it and explains what was done. Payment is by bank transfer on invoice.
Call now for a clear price and a straight answer. Gas Safe registered 961481, £10m insured, 20 years' experience.