Compare quotes from multiple verified Dulwich plumbers
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Lost heating or hot water in Dulwich with no leak to blame? This page connects you with verified, insured, Gas Safe registered engineers covering SE21, SE22 and SE24 — for boiler fault-finding and repair, done legally and diagnosed properly.
✅ Checked before listing — identity, insurance, trading presence, Gas Safe registration.
✅ Workmanship guarantee badges on listings — 1, 3, 6 or 12 months.
⚠️ Smell gas or suspect a leak? Leave the property and call the National Gas Emergency Service on 0800 111 999 from outside — free, 24/7.
Worried about carbon monoxide (headaches, dizziness, a lazy yellow flame instead of crisp blue)? Treat it as an emergency too — full steps in Safety first ↓.
→ Contact verified Dulwich boiler engineers ↓ — scroll to the verified list below.
Are you a plumber covering Dulwich?
Use the search above to find a local expert
Use the search above to find a local expert.
Coverage: SE21 (Dulwich Village, West Dulwich), SE22 (East Dulwich) and SE24 (Herne Hill / North Dulwich edge), across the Southwark and Lambeth parts of Dulwich.
What this covers: no heating or hot water with no leak, boiler lockouts and fault codes, low pressure, kettling and noise, intermittent firing, pump and diverter-valve faults, and diagnosing whether a fault is a repair or a replacement.
Not sure which page you need? If it’s the wider system (cold radiators, no leak), start with Central Heating Repair; for the annual service, Boiler Servicing; if you’re replacing the boiler, Boiler Installation.
Costs: repairs are priced per job — see What it costs ↓ for an editorial estimate.
Availability: listed engineers set their own hours. Confirm current attendance, appliance competence and whether likely parts are available before booking.
Jump to: Who can legally repair a boiler ↓ · Repair or replace in Dulwich ↓ · Safety first ↓ · Find an engineer by district ↓ · What it costs ↓ · FAQs ↓
Who can legally repair a gas boiler
A gas boiler repair is not general plumbing — it’s gas work, and the law is specific. Only a Gas Safe registered engineer may legally work on gas appliances and pipework; the Gas Safe Register is the official list of businesses allowed to do it.1 The Health and Safety Executive draws the line clearly: a non-registered person may carry out separate wet work on radiators and water pipework, but any work on the gas boiler itself — including the final connection of the water pipework to the boiler — must be carried out by a suitably qualified Gas Safe registered engineer.2 Always ask to see the engineer’s Gas Safe ID card and check they’re qualified for your appliance — every gas engineer listed here has had that registration verified before listing.
If you rent, report a landlord-provided boiler fault promptly to the landlord or agent. Heating and hot-water installations supplied by the landlord are generally the landlord’s responsibility; tenant-owned appliances and tenant-caused damage may fall outside that duty. Annual gas-safety duties remain separate.34
Repair or replace — the Dulwich picture
Not every boiler fault is worth repairing, and a good engineer will tell you when it isn’t. The judgment turns on the boiler’s age, the cost of the part against a new unit, and how often it’s failing — and if replacement is the answer, a new boiler brings its own rules. Under the government’s Boiler Plus standard, GOV.UK requires a new domestic gas boiler in England to be at least 92% efficient with time and temperature controls, and a new combi to include one additional efficiency measure.6 Our Should I Repair or Replace My Boiler? guide walks through the trade-off.
Boiler noise, lockout and poor performance have several possible causes, including controls, sensors, pumps, circulation, trapped air, sludge, scale, gas-supply or combustion faults. An engineer should check controls and visible leaks, read manufacturer fault codes, test the expansion vessel and pressure-relief discharge, and distinguish boiler-component faults from system-circulation faults before recommending cleaning or replacement. Power flushing or chemical cleaning should follow evidence of contamination or poor water quality, not noise alone. BS 7593 inhibitor protects the primary heating circuit against corrosion and scale; separate suitable treatment may be required for feed water to water heaters and the domestic-hot-water side of combination boilers in hard-water areas.813 If the specific property is on Dulwich Estate land, a new or relocated flue may require an Estate licence.9
Safety first
If you smell gas, or suspect a leak, the National Gas Emergency Service sets out the sequence: don’t touch electrical switches on or off, use a naked flame or smoke; open doors and windows if it’s safe; turn the gas off at the meter control valve if you can reach it safely (not in a cellar); leave if the smell is strong or you feel unwell; and call 0800 111 999 from outside — free, 24/7.10
Carbon monoxide is a separate danger — colourless, odourless, produced when a fuel-burning appliance runs badly, and a poorly-running boiler can produce it. Warning signs include headaches, dizziness and nausea that ease when you leave the house, and a lazy yellow flame or sooty staining. The HSE strongly recommends CO alarms as a useful precaution. Choose an alarm complying with BS EN 50291 and install and maintain it according to the manufacturer’s instructions.11 If a boiler is behaving strangely and you suspect CO, treat it as an emergency, get fresh air and call 0800 111 999.
Find a verified engineer by district
East Dulwich (SE22) — boiler type and location vary by property. Check manufacturer access, controls and whether a concealed or boxed flue has the required inspection access.
Dulwich Village & West Dulwich (SE21) — do not assume a system type from house size. Confirm whether the boiler is private, whether cylinders or communal plant are involved, and whether a flue alteration affects Estate-controlled fabric.
Flats & conversions — flues may pass through concealed routes and need compliant inspection panels. In a managed block, communal heating or plant faults go to the managing agent or block contractor, not a private boiler engineer.
Herne Hill edge (SE24) — the Lambeth side of Dulwich, similar stock; confirm your postcode so you reach an engineer covering your street and the right council for any landlord repair.
What it costs
Boiler repairs are priced per job, depending on the fault and parts. 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. Confirm the price before work starts, and see How to Read a Plumbing Quote and the London Plumbing Costs & Compliance Guide 2026.
| Boiler repair (indicative) | Typical range |
|---|---|
| Diagnostic / call-out (daytime) | £70–£130 |
| Common part replacement (e.g. thermostat, sensor) | £120–£280 |
| Pump, diverter valve or fan replacement | £180–£450 |
| Out-of-hours no-heat call-out | £130–£250+ |
Dulwich is inside the London-wide Ultra Low Emission Zone, which Transport for London operates across all London boroughs; a non-compliant vehicle incurs the daily ULEZ charge.12 Dulwich sits outside the central London Congestion Charge zone.
VerifiedPlumbers is a directory that connects you with verified engineers; it doesn’t carry out the work itself, and enquiries go directly to the engineer with no middleman fee.
Frequently asked questions
No. A non-registered plumber may carry out separate wet work on radiators and water pipework, but any work on the gas boiler itself — including the final connection of the water pipework to the boiler — must be carried out by a suitably qualified Gas Safe registered engineer. Always check the ID card and appliance category.
It depends on the age, the part, and how often it’s failing. A verified engineer diagnoses first. If replacement is the sensible option, a new boiler must meet the Boiler Plus efficiency and controls standard.
Report a landlord-provided heating or hot-water fault to the landlord or council. Tenant-owned appliances and tenant-caused damage may be treated differently, so confirm ownership and cause.
Hard water can contribute to limescale on the domestic-water side of some boilers, but kettling and lockouts also have circulation, sludge, sensor, pump and component causes. Primary-circuit inhibitor under BS 7593 controls corrosion and primary-system deposits; it is not by itself the treatment for domestic-water limescale. The engineer should test before specifying treatment.
If your home is on Dulwich Estate land and the replacement involves a new or relocated flue, the Estate lists boiler flues among the works needing a Scheme of Management licence — separate from and additional to any Southwark or Lambeth council approval.
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Related services in Dulwich
- Central Heating Repair in Dulwich — cold radiators, no heat, no leak
- Boiler Servicing in Dulwich — annual service and landlord checks
- Boiler Installation in Dulwich — new and replacement boilers
- Emergency Plumber in Dulwich — no heat or hot water out of hours
- All plumbing services in Dulwich — the full directory
Related guides
- Should I Repair or Replace My Boiler? — the trade-off
- London Hard Water Guide — scale and boiler faults
Boiler repair requires a Gas Safe engineer, manufacturer-led diagnosis and clear responsibility boundaries. Controls, expansion vessel, pressure-relief discharge, circulation, flue access and water quality should be tested before parts or power flushing are recommended. Communal plant goes through the block manager, and any Estate flue consent depends on the specific property and work.
→ Contact verified Dulwich boiler engineers ↑ — see the verified list above.
Last reviewed: July 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 — Gas Safe Register, the Health and Safety Executive, the Landlord and Tenant Act 1985, GOV.UK (Boiler Plus), the HHIC Benchmark scheme, The Dulwich Estate, the National Gas Emergency Service, Thames Water, the London Borough of Southwark and Transport for London. Source links are provided within this page where relevant.
Sources & further reading
1. Gas Safe Register (only Gas Safe registered engineers may work on gas). https://www.gassaferegister.co.uk/
2. HSE — Gas safety check: who can do it? (wet work vs Gas Safe boiler work). https://www.hse.gov.uk/gas/landlords/safetycheckswhocan.htm
3. Landlord and Tenant Act 1985, section 11 (landlord responsible for heating and hot water installations). https://www.legislation.gov.uk/ukpga/1985/70/section/11
4. HSE — Gas safety checks: who needs them? (landlord annual check; regulation 36 GSIUR 1998). https://www.hse.gov.uk/gas/landlords/safetycheckswho.htm
5. Southwark Council — Report an emergency repair (council tenant repairs 0800 952 4444). https://www.southwark.gov.uk/housing/repairs-maintenance-and-home-safety/repairs/report-repair/report-emergency-repair
6. GOV.UK — Boiler Plus factsheet (92% ErP; controls; combi additional measure). https://assets.publishing.service.gov.uk/media/5b2cc1e2ed915d586e2d8fe9/Boiler_Plus_Factsheet_v3.pdf
7. Thames Water — Hard water (all water in the region is hard). https://www.thameswater.co.uk/help/water-and-waste-help/water-quality/hard-water
8. HHIC Benchmark code of practice (system inhibitor to BS 7593; warranty). https://www.hhic.org.uk/uploads/5D9B41557255E.pdf
9. The Dulwich Estate — Alterations to your home (boiler flue installation needs a Scheme of Management licence). https://www.thedulwichestate.org.uk/property-on-the-estate/residential-leasehold/alterations-to-your-home
10. National Gas — Emergency contacts (gas-emergency sequence; 0800 111 999). https://www.nationalgas.com/emergency-contacts
11. HSE — Domestic gas frequently asked questions (CO alarm to BS EN 50291). https://www.hse.gov.uk/gas/domestic/faqs.htm
12. Transport for London — Ultra Low Emission Zone (operates across all London boroughs). https://tfl.gov.uk/modes/driving/ultra-low-emission-zone
13. HM Government — Approved Document L, Volume 1 (primary-circuit inhibitor and separate hard-water treatment for water heaters/combi domestic-hot-water circuits). https://www.gov.uk/government/publications/conservation-of-fuel-and-power-approved-document-l