Harrow · HA1 · Greater London
Get a fixed-price quote for a new boiler online and have a Gas Safe registered engineer fit it at your Harrow home – often as soon as the next day. Replacement gas boilers in Harrow cover combi swaps, system boilers for larger houses, back boiler removals and full heating upgrades.
Harrow is classic Metroland, with semis in Pinner and Rayners Lane, conservation areas on the Hill, and flats in the centre and Wealdstone. We install Vaillant, Worcester Bosch, Ideal, Baxi and Viessmann boilers across the HA postcodes.
Metroland semis are usually a simple combi swap, where the Vaillant ecoFIT pure is a popular, quiet choice. Detached houses in Pinner and Stanmore with more bathrooms tend to suit a Worcester Bosch Greenstar system boiler and cylinder. On Harrow on the Hill, conservation rules can affect flue positions, so we plan around them.
Boiler prices in Harrow depend on the home more than the postcode. A flat in Wealdstone, a Metroland semi in Pinner and a detached house in Stanmore call for different boilers, and flue, pipework and controls all change the final price. Like-for-like combi swaps start from £1,759 fitted, while Worcester Bosch Greenstar 4000 packages start from around £2,450. The price on your online quote is the price you pay. Extras are never slipped in at the end.
| Installation type | What’s involved | Price from | Time on site |
|---|---|---|---|
| Like-for-like combi swap | Replace an existing combi in the same position, with new flue, filter and controls | £1,759 | 1 day |
| Conventional or system to combi | Remove tanks and cylinder, cap off pipework, fit combi and upgrade gas supply if needed | £2,350 | 1–2 days |
| Back boiler replacement | Remove back boiler and fire, make good, fit new boiler in a new location | £2,795 | 2+ days |
| System boiler with cylinder | Suited to larger homes with multiple bathrooms; new or replacement unvented cylinder | £2,995 | 1–2 days |
| Boiler relocation | Move the boiler to a loft, garage or new room with new gas, flue and condensate runs | £2,250 | 1–2 days |
These are starting prices for a standard installation by a Gas Safe registered engineer; your online quote confirms the exact cost for your home.
Get a new boiler on finance in Harrow from £23.26 a month. As an example, a £1,799 boiler spread over 10 years at 9.9% APR works out at £23.26 per month. Subject to status, you can pick a shorter term, interest-free finance or buy now, pay later. See our boiler finance options for the full details.
Harrow’s housing is more uniform than much of London, but the details matter. These are the jobs we fit most.
A like-for-like combi swap with a filter and new controls gives the biggest saving for the least disruption.
A compact combi in a cupboard keeps the footprint small, with flue routes checked against lease rules.
A system boiler with an unvented cylinder handles busy mornings and several bathrooms without pressure loss.
Local boiler installers
Harrow is north-west London’s Metroland borough, built around the railway with long streets of inter-war semis in Pinner, Rayners Lane and Kenton. Harrow on the Hill’s historic village and school give the centre a distinctive character, while Wealdstone and the town centre have a growing number of flats, and Stanmore has larger detached houses on the green edge.
Most Harrow homes are the same era and shape, but extensions, loft conversions and flat conversions make each job different. When we price boiler replacement in Harrow we survey the layout, the flue route and the hot water demand first, so your fixed price covers the right boiler.
With your boiler and installation date chosen online, a Gas Safe registered engineer removes the old boiler, fits and commissions the new one, registers the warranty and notifies Building Control, with the compliance certificate sent afterwards.
Harrow is classic Metroland: tree-lined semis, hilltop conservation areas and busy flats around the town centre. Here is what we see most.
Harrow water is very hard, so scale builds up quickly inside combi heat exchangers. With a combi, we check hardness for your postcode and fit a scale reducer if it’s over 200ppm.
These 1930s semis usually have a roomy airing cupboard, so a combi swap is often straightforward. We check mains pressure first.
Harrow on the Hill and Pinner Village have design controls that affect flues. We plan a discreet route and flag any consent needed.
New and converted flats need compact combis and carefully planned flues. We check building rules and ventilation before quoting.
Larger houses in Stanmore often have several bathrooms, so we fit a system boiler and cylinder to keep hot water strong.
Extensions raise heating and hot water demand. We re-size the boiler for the whole home, not just the original rooms.
Our Gas Safe engineers cover the whole borough, from Harrow and Wealdstone to Pinner, Stanmore and Rayners Lane. See all our service areas.
Red pin: Harrow town centre. Green pins: nearby towns we cover — tap a pin to see how far each town is from Harrow. The shaded circle shows roughly 8 miles around Harrow.
We also cover London as a whole, plus neighbouring Brent (about 4 miles), Hillingdon (about 6 miles) and Barnet (about 8 miles).
Often as soon as the next day, depending on the boiler you choose and engineer availability in the HA1 area. Complete the online quote, choose a date that suits you, and if you have no heating or hot water we put your booking first.
All HA1 postcodes plus HA2, HA3, HA5 and HA7, including Pinner, Stanmore, Wealdstone, Kenton and Rayners Lane, and nearby areas such as Hillingdon, Barnet and Watford. As part of a nationwide Gas Safe engineer network, we can also help outside these areas.
Harrow tap water is very hard, normally above 200ppm. You can check your postcode on your supplier’s hardness checker. Where it is above 200ppm, we fit a scale reducer with a combi boiler, in line with Building Regulations guidance.
Yes. If you have a back boiler, we take out the unit and the fireplace it’s built into and cap off the old flue and pipes safely. After that, a modern combi or system boiler is fitted in a more convenient position. Expect it to run longer than a simple swap. Before work starts, we tell you how long it should take.
Boiler replacement is notifiable work under Building Regulations, and your Gas Safe registered engineer handles the notification, followed by a compliance certificate. Planning permission is not normally needed for a like-for-like swap, but Harrow on the Hill, Pinner Village and Stanmore have conservation areas, so check with Harrow Council first if a flue would face the street.
Yes. Boiler finance in Harrow includes interest-free, 9.9% APR and buy now, pay later options, with deposits from £0 – see our boiler finance page. All finance is subject to status.
Yes. The engineer disconnects the old boiler, removes it and disposes of it responsibly, together with unneeded tanks or cylinders when you switch to a combi.
All boilers we install come with a manufacturer-backed warranty, typically between 5 and 10+ years depending on the model. Keeping it valid usually means an annual service – our boiler cover plans take care of that for you.
Yes. We also replace oil and LPG boilers for properties that aren’t on the gas grid. For oil we send an OFTEC registered engineer; for LPG, a Gas Safe registered engineer with LPG competence. See our oil boiler installation and replacement and LPG boiler installation and replacement pages for more detail.
Tell us about your home, see fixed-price replacement boiler packages for Harrow and book the installation date that suits you – all online, in a few minutes.