New boiler quotes in Harrow.
Three quotes from Gas Safe registered engineers who actually cover your postcode, not a call centre eighty miles away.
- Covering HA1, HA2, HA3, HA5, HA7, HA8 and the wider Greater London
- Your job reaches them in about 60 seconds
- Three engineers maximum, then it closes
- Every one checked on the Gas Safe Register
Get three Harrow quotes.
- Three quotes from Gas Safe engineers in your postcode
- Compare prices and opinions before you commit
- A maximum of three, then it closes
- Free to you, and no obligation
Engineers covering Harrow.
Every one checked on the Gas Safe Register before they join.
- Gas Safe registration number verified against the public register
- A registered business with a real address, not a mobile and a van
- Coverage confirmed for the postcode areas they say they work in
- We ask homeowners how the job went, and act on the answer
You can check any engineer's registration yourself at gassaferegister.co.uk before work begins. Ask to see the card. Any decent engineer expects you to.
What a boiler swap usually looks like in Harrow.
Harrow is Metroland. Census 2021 puts 37 per cent of homes as semi-detached, the highest share of any borough in this part of London, with 17 per cent terraced, 11 per cent detached and 26 per cent in purpose-built blocks of flats. Most of the borough was built between the wars once the Metropolitan Railway opened up Pinner, Rayners Lane, North Harrow, Kenton and Harrow Weald, and the streets there are long runs of 1920s and 1930s semis and chalet-style houses. Harrow on the Hill and old Pinner village are older, with Georgian and Victorian houses, and Wealdstone has Victorian and Edwardian terraces. Newer flats cluster around Harrow town centre and Wealdstone.
The inter-war semi sets the pattern for boiler work across Harrow. Many still have a hot water cylinder in the airing cupboard and a cold tank in the loft, so cylinder-to-combi conversion is common where there is one bathroom and good mains pressure, and a system boiler with an unvented cylinder is chosen where a loft conversion has added a second shower, which is widespread in Pinner, Kenton and Rayners Lane. Kitchens in these houses are usually at the back, so the flue goes out through the rear wall and needs to clear the neighbour's boundary and any side-return window. Census 2021 shows 78 per cent of Harrow households on mains gas only, so almost every job is a gas-to-gas swap.
We deliberately don't put a figure on this page, because nobody can price a boiler from a postcode. The cost calculator will give you a realistic range for a property like yours in under a minute, and three quotes for your actual job give you the real answer.
Getting three quotes matters more on a conversion
On a straight replacement the prices tend to cluster. On a cylinder-to-combi conversion they do not: how the engineer plans to route the pipework, whether a system flush is included and what happens to the cupboard afterwards can each move the number by hundreds. Three quotes is not about haggling. It is about seeing three different opinions on how the work should be done.
Whoever you go with must be Gas Safe registered. It is against the law for anyone else to work on your gas boiler, and you can check any engineer's registration number yourself before they start.
Finding a boiler engineer in Harrow
Our engineers cover HA1, HA2, HA3, HA5, HA7, HA8 and the wider Greater London area, and those codes are examples rather than a limit. Rather than ringing round yourself, you fill in one form and we pass it to up to three Gas Safe registered engineers who work in your postcode. They contact you, they quote, and you decide.
Ask all three the same questions
Is the price fixed or an estimate? Does it include a power flush or just a chemical clean? Is a magnetic filter included, since most manufacturer warranties require one? Who notifies building control? A good engineer in Harrow will not mind being asked, and one who bristles has told you something useful.
Water and heating in Harrow
Harrow is supplied by Affinity Water from chalk aquifer boreholes, and published readings for the borough are among the highest in London at well over 300 mg/l as calcium carbonate, which is very hard. Limescale will coat a combi's plate heat exchanger fast here, so a scale reducer on the cold main is treated as standard and most boiler makers expect one for the warranty to hold.
Planning, flats and the edges of Harrow
Harrow has 30 conservation areas and 15 of them carry Article 4 directions, which remove permitted development rights for alterations to the front of houses. They are grouped around Harrow on the Hill, including Harrow School, Roxeth Hill, Sudbury Hill and South Hill Avenue; Pinner, including Waxwell Lane and Rayners Lane; Stanmore and Edgware, including Stanmore Hill, Old Church Lane, Little Common, Kerry Avenue and West Drive; and Harrow Weald, including the Grimsdyke Estate and Brookshill. In these streets a flue on a front elevation will normally need a planning application. Building control for the borough is the London Borough of Harrow and gas is distributed by Cadent.
Areas of Harrow this covers
Harrow on the Hill, Wealdstone, Kenton, Harrow Weald, Rayners Lane, Pinner, Hatch End, Stanmore, North Harrow and South Harrow, and everywhere else in HA1, HA2, HA3, HA5, HA7, HA8. The districts are Harrow itself; a job just outside them still reaches engineers who cover that postcode.
Harrow questions.
Is Harrow's water hard enough to need a scale reducer on a new boiler?
Yes, and more so than most of London. Affinity Water draws Harrow's supply from chalk boreholes and published readings for the borough sit well above 300 mg/l as calcium carbonate, which is very hard. That dissolved chalk drops out as limescale wherever water is heated, and in a combi it settles on the plate heat exchanger and slowly restricts hot water flow. Boiler manufacturers generally require a scale reducer or inline inhibitor on the cold main at this level, and several make it a warranty condition. A magnetic filter on the heating return handles sludge, not scale, so both are normally fitted.
Are the 1930s semis in Pinner and Rayners Lane usually combi or system boiler?
Both are common, and the house itself decides. An unextended semi with one bathroom in Rayners Lane or North Harrow is normally converted to a combi, which removes the cylinder and loft tank and frees the airing cupboard. Where the house has a loft conversion with an en-suite, as many in Pinner and Hatch End now do, a system boiler feeding an unvented cylinder keeps pressure steady when two showers run together. The engineer will measure the incoming mains flow and pressure first, because a combi is only as good as the main feeding it, and older lead or narrow-bore supply pipes in these streets can be the limiting factor.
What does a new boiler cost in Harrow?
It depends far more on the job than the town. A straight combi-for-combi swap sits at the bottom of the range; a cylinder-to-combi conversion sits well above it, and only an engineer standing in your house can see which one you have. The cost calculator gives you a realistic range in under a minute, and comparing 3 quotes for your actual job gives you the real answer.
Which postcodes in Harrow do you cover?
Harrow is HA1, HA2, HA3, HA5, HA7, HA8, and we match on the outward code, so a job in HA1 only goes to engineers who have told us they cover HA1. Those districts are the town itself rather than a service boundary. If your postcode isn't listed, enter it anyway: we place jobs across the UK, not only in the towns we have a page for.
How quickly can someone come out in Harrow?
Your job reaches engineers covering HA postcodes within about a minute of you submitting it. How soon one of them can actually fit a boiler depends on their diary and on the job, so we don't promise a date we don't control. If your boiler has failed completely, say so on the form and it is flagged as urgent.
Are your Harrow engineers Gas Safe registered?
Yes. Every engineer on our network is on the Gas Safe Register and we check the number against the public register before any job is sent to them. It is illegal for anyone else to work on your gas boiler. Ask to see their ID card and check it yourself at gassaferegister.co.uk before work starts.
Do you own the property in Harrow?
This is the one thing we have to know before anything else. A boiler replacement is a permanent change to the property, so it has to be authorised by whoever owns it - which means we can only arrange quotes for the homeowner, or for someone acting on the owner's behalf. Landlords are welcome to use the form for a property they let. If you answer no, we stop there rather than pass your details to an engineer who would not be able to take the job.
Three Harrow quotes, thirty seconds.
Free, no obligation, and only three engineers ever get your details.