Replacing an old boiler, or fitting a new heating system from scratch? This page connects you with verified, Gas Safe registered engineers across Havering who install boilers compliantly, from Romford and Hornchurch to Upminster and Rainham.

✅ Checked before listing — identity, insurance, trading presence, Gas Safe (where relevant).
How we verify →
✅ Workmanship guarantee badges on listings — 1, 3, 6 or 12 months

⚠️ Smell gas, or think a boiler’s producing fumes? Don’t touch electrics or switches, open a window, and from outside call the National Gas Emergency Service on 0800 111 999. Feel unwell with headaches or dizziness that ease when you leave the house? Treat it as possible carbon monoxide — full safety steps in Safety first ↓.

→ Find a verified Havering boiler installer — see the verified list below.

Coverage: RM1, RM2, RM3, RM4, RM5, RM6, RM7, RM11, RM12, RM13, RM14 — Romford, Gidea Park, Collier Row, Harold Hill, Harold Wood, Hornchurch, Elm Park, Upminster, Cranham, Rainham, South Hornchurch and the rural-edge villages.
Boiler installation covered: replacing a like-for-like boiler, swapping boiler type (combi, system or heat-only), sizing a new boiler to the home, Boiler Plus-compliant controls, flue and condensate routing, gas-supply and pipework upgrades, system flushing and protection, Building Regulations notification, and warranty registration. Every listed installer is Gas Safe registered. For a boiler installation in Havering, use the verified list above.
Not sure which page you need? If your existing boiler has a fault, that’s Boiler Repair; if your radiators or system need attention but not the boiler, Central Heating Repair; for an annual service or gas safety check, Boiler Servicing.
Costs: see What it costs ↓ for an editorial estimate.

Which boiler do you need?

The right boiler depends on the home, not just the budget — and getting the type and size right is the single biggest factor in whether you’re happy with it for the next decade.

• Combi boiler. Heats water on demand with no separate cylinder or tank — compact, efficient, and well suited to smaller homes and flats with one bathroom. It can struggle to run two showers at once, so it’s less ideal for a busy multi-bathroom house.
• System boiler. Works with a hot-water cylinder (but no loft tank), giving stored hot water that several outlets can draw at once — better for larger homes with more than one bathroom.
• Heat-only (regular/conventional) boiler. Uses a cylinder and a loft feed/expansion tank — common in older Havering houses with a traditional system, and sometimes the simplest like-for-like replacement.

Sizing matters as much as type. An oversized boiler cycles wastefully; an undersized one can’t keep up. A good installer sizes to the home’s heat demand and hot-water needs rather than just matching the old output — and for a combi that means checking the hot-water flow rate and incoming mains pressure, not just the heating output, since a combi that’s starved of mains flow will disappoint at the tap. If you’re weighing combi against a cylinder system, our combi vs system boiler guide walks through it, and the boiler repair or replace guide helps if you’re not sure a replacement is needed at all.

What a compliant installation involves

A boiler swap is more than lifting one off the wall and hanging another — and a fair amount of what a good installer does is driven by regulation, which is worth understanding so you know what you’re paying for.

It must meet Boiler Plus. Under the government’s Boiler Plus standard, in force in England since April 2018, a new or replacement gas boiler must be at least 92% ErP efficiency, must have time and temperature controls (a programmer and room thermostat as a minimum), and a new combi boiler must include one additional efficiency measure — weather compensation, load compensation, flue gas heat recovery, or smart controls with automation and optimisation functions.¹

It must be notified under Building Regulations. Installing or replacing a boiler is notifiable building work. Because a Gas Safe registered installer belongs to a Competent Persons Scheme, they can self-certify the work — notifying the local authority on your behalf, after which a Building Regulations compliance certificate is issued to you. The Gas Safe Register sets out that in England and Wales the local authority must be informed when a heat-producing appliance is installed, and a registered business self-certifies (notifies) within 30 days so the compliance certificate can be issued; if you used an installer not in such a scheme, your local authority building control would have to inspect and approve it instead.² Keep that certificate — you’ll need it when you sell or remortgage.

You should get a commissioning certificate. On completion, the installer should commission the boiler and complete a commissioning certificate — commonly a Benchmark certificate, the heating industry’s commissioning checklist — recording that it’s been set up correctly.³ This is usually what validates the manufacturer’s warranty — most major brands require evidence of proper commissioning before they’ll honour a claim — so it matters that it’s filled in and you keep it.

The wider work a swap can involve. Changing boiler type or position often means new flue and condensate routing, a gas-supply pipe upgrade (a modern combi may need a larger-diameter gas pipe than an old boiler), and a system flush — which brings us to the local angle. A point on siting: a new flue has to terminate safely away from windows, doors and boundaries, and an external condensate run should be kept short, correctly graded to fall to a suitable drain, and insulated where it’s exposed (the reason frozen-condensate lockouts are a winter problem). Converting from an old heat-only system to a combi also means removing the cylinder and any loft tanks, altering pipework, and confirming the mains can deliver the flow a combi needs.

Hard water and protecting a new boiler

It’s worth installing a new boiler with Havering’s water in mind. Many Havering homes are on a hard-water supply, including Essex & Suffolk Water’s hard-water area, where the company confirms hardness leaves limescale.⁴ Fitting a shiny new boiler onto an old, sludged-up system is a false economy — the debris circulates straight into the new heat exchanger.

A good installation on a Havering system therefore usually includes a system flush (or power-flush where there’s heavy sludge) before the new boiler goes on, a central-heating inhibitor added to protect it, and a magnetic system filter fitted to catch circulating debris — sometimes alongside a scale reducer on the incoming main. This isn’t just good practice: many manufacturers’ warranties require the system to be cleaned and an inhibitor applied (the Benchmark commissioning checklist records it), so skimping on it can affect both performance and the warranty.

Safety first

Installing a boiler is gas work, so the safety framework here is the reason it’s restricted to registered engineers.

Only a Gas Safe registered engineer should install your boiler. The Gas Safe Register is the official register of engineers legally allowed to carry out gas work in the UK; it replaced CORGI in 2009, and registration is a legal requirement under the Gas Safety (Installation and Use) Regulations 1998.⁵ A registered engineer carries a Gas Safe ID card showing the work they’re qualified to do — you’re entitled to ask to see it before work starts.

If you smell gas or suspect a leak, follow the Health and Safety Executive’s emergency sequence:

1. Don’t touch electrical switches — on or off — light a naked flame, or smoke.
2. Open doors and windows to ventilate, if it’s safe.
3. If you know where the gas meter control valve is and can reach it safely, turn the gas off at the meter (not if it’s in a cellar).
4. Leave the property if the smell is strong or you feel unwell.
5. Call the National Gas Emergency Service on 0800 111 999 from outside — free, 24/7. National Gas sets out this sequence and will send an engineer to make the situation safe.⁶

Carbon monoxide (CO) is colourless and odourless, produced when a gas appliance burns incompletely — which is one reason a correct, commissioned installation matters. Warning signs include headaches, dizziness, nausea or breathlessness that ease when you leave the house, and a lazy yellow or orange flame instead of crisp blue. A new install should include a CO alarm that complies with BS EN 50291, sited per the manufacturer’s instructions.⁷

If you’re a landlord, a boiler you provide must be kept safe with an annual gas safety check by a Gas Safe registered engineer and a Gas Safety Record. The HSE sets out that gas safety duties for landlord-provided gas appliances, flues and pipework remain the landlord’s responsibility, with annual checks on the relevant gas fittings.⁸

Find a verified boiler installer by district

Havering is an outer-London suburban borough, with many suburban houses alongside flats, maisonettes and newer developments — and the right installation reflects the local stock and its hard-water supply. Here’s the local picture.

Romford (RM1, RM2, RM7) — town-centre flats above shops and a wide spread of suburban housing in Gidea Park, Rise Park and Mawneys. Flats and maisonettes usually suit a wall-hung combi, but flue routing, condensate runs and gas-pipe access in a block can shape the job — and may need freeholder or managing-agent agreement before work starts.

Hornchurch & Elm Park (RM11, RM12) — Hornchurch and Elm Park include a lot of inter-war-style suburban housing — semis, bungalows and detached houses — a good number still on older heat-only systems with a cylinder and loft tank. These are the classic “combi conversion or keep the cylinder?” decisions, and the existing system usually needs a thorough flush before a new boiler goes on.

Upminster & Cranham (RM14) — larger suburban homes with more bathrooms, where a system boiler and cylinder often makes more sense than a single combi that can’t serve two showers at once. Sizing to the real hot-water demand matters here.

Rainham, South Hornchurch & Beam Park (RM13) — older mixed stock beside new-build Beam Park homes. New-builds will already have modern, Boiler Plus-compliant combis (and any swap during warranty should go through the manufacturer’s approved route); older Rainham stock is more often where a full replacement is due.

Harold Hill, Harold Wood & Collier Row (RM3, RM5) — includes post-war estate housing, maisonettes and flats, plus mid-century houses and 1930s Collier Row stock. Combi swaps are common, with flue and condensate routing — sometimes through an extension or shared fabric — a factor in maisonettes and blocks. In a converted or extended house, where the boiler can move is often limited by where a compliant flue can terminate and whether the condensate can fall to a suitable drain.

Gidea Park, Emerson Park & the rural edge (RM2, RM4) — larger detached houses that often need higher-output system boilers, occasionally more than one. Some rural-edge properties out toward Havering-atte-Bower, Noak Hill, Corbets Tey and North Ockendon may be on oil or LPG rather than mains gas where the network thins out — worth confirming the fuel before booking, as it changes the installation and the registration category needed.

If you’re near the Romford / Barking & Dagenham boundary at Rush Green, confirm your postcode is RM and within Havering before booking.

What it costs

The figures below are an editorial estimate only, to help you sense-check a quote — they are not regulated rates, not market data, and not a published cost survey. Always confirm the price before work starts, and see how to read a plumbing quote and our London plumbing costs guide.

These vary widely with boiler make and output, the amount of pipework, flue and condensate changes, and system protection. Havering is outside the central London Congestion Charge zone, but like every Greater London borough it sits inside the London-wide Ultra Low Emission Zone (ULEZ), which the TfL ULEZ scheme operates across all London boroughs (excluding the M25 itself). A non-compliant vehicle may incur the daily charge, so it’s reasonable to ask whether any emissions-zone charge is included in a quote.⁹

When you contact an installer from this directory, you can ask for an itemised quote covering the boiler, controls, flushing and protection, flue and gas-supply work, the Building Regulations notification and the warranty registration — you’re not obliged to proceed until you’ve agreed it. VerifiedPlumbers is a directory that connects you with verified, Gas Safe registered engineers; it doesn’t carry out the work itself.

Frequently asked questions

Related services in Havering

• Boiler Repair in Havering — a fault on your existing boiler
• Boiler Servicing in Havering — annual service and gas safety check
• Central Heating Repair in Havering — radiators, pumps and system faults
• Emergency Plumber in Havering — urgent no-heat or gas situations
• All plumbing services in Havering — the full directory

Related guides

• Combi vs System Boiler — which suits your home
• Boiler Repair or Replace? — whether you need a new one at all
• How to Read a Plumbing Quote — what an install quote should itemise
• London Plumbing Costs & Compliance Guide 2026 — what plumbing and heating work typically costs

A new boiler is a decade-long decision, and most of what separates a good installation from a cheap one is invisible once the casing’s on: the right type and size for the home, a flushed and protected system, a compliant flue and gas supply, and the paperwork — Boiler Plus compliance, the Building Regulations certificate, and a commissioning certificate that validates the warranty. The verified engineers listed above install boilers across the Havering RM postcodes listed above, each one Gas Safe registered for the gas work they carry out.

↑ Find a verified Havering boiler installer — see the verified list above.

← Back to all plumbing services in Havering

Last reviewed: May 2026 by Adiel Khan — SFEDI-accredited business advisor, 20+ years’ experience (South East Enterprise Ltd) and operator of VerifiedPlumbers. LinkedIn ↗

This page is checked for compliance and regulatory accuracy against the bodies and regulations cited on it — Boiler Plus (GOV.UK), the Gas Safe Register, the Building Regulations, the Gas Safety (Installation and Use) Regulations 1998, the HSE, the National Gas Emergency Service, Essex & Suffolk Water and Transport for London. Source links are provided within this page where relevant.

Sources & further reading

1. GOV.UK — Boiler Plus factsheet (new/replacement gas boilers in England from April 2018 must be at least 92% ErP, with time and temperature controls; new combi boilers need one additional efficiency measure). https://assets.publishing.service.gov.uk/media/5b2cc1e2ed915d586e2d8fe9/Boiler_Plus_Factsheet_v3.pdf
2. Gas Safe Register — Building Regulations certificates (in England and Wales the local authority must be informed when a heat-producing appliance is installed; a registered business self-certifies within 30 days and a Building Regulations compliance certificate is issued). https://www.gassaferegister.co.uk/gas-safety/gas-safety-certificates-records/building-regulations-certificate/
3. Planning Portal — Building regulations: boilers and heating (on completion the installer should produce a commissioning certificate such as a Benchmark certificate and notify building control directly or via a Competent Person Scheme). https://www.planningportal.co.uk/permission/common-projects/boilers-and-heating/building-regulations/
4. Essex & Suffolk Water — Hard water (confirms a hard-water supply area; limescale forms from hard water). https://www.eswater.co.uk/hardwater
5. HSE — Gas safety (home owners) (anyone employed to work on gas appliances in domestic premises must be a Gas Safe registered engineer; registration is required under the Gas Safety (Installation and Use) Regulations 1998). https://www.hse.gov.uk/gas/domestic/faqownerocc.htm
6. National Gas — Emergency contacts (gas-emergency sequence; 0800 111 999, 24/7). https://www.nationalgas.com/emergency-contacts
7. HSE — Domestic gas frequently asked questions (CO alarm to BS EN 50291). https://www.hse.gov.uk/gas/domestic/faqs.htm
8. HSE — Landlords’ responsibility for gas safety (annual checks on landlord-provided gas appliances, flues and pipework). https://www.hse.gov.uk/gas/landlords/
9. Transport for London — Ultra Low Emission Zone (ULEZ operates across all London boroughs, excluding the M25; daily charge for non-compliant vehicles). https://tfl.gov.uk/modes/driving/ultra-low-emission-zone