Boiler Repair London — Gas Safe Registered
Gas Safe registered engineers for boiler breakdowns, pressure faults, no hot water and annual servicing across all 33 London boroughs. We carry parts for Worcester Bosch, Vaillant, Ideal, Baxi and Glow-Worm on most call-outs — aiming to fix on the first visit.
Gas Safe Registered
All gas engineers Gas Safe ID 123456
24/7 Emergency
Plumbers available every day of the year
No Call-Out Fee Over 2 Hours
£60 waived on jobs exceeding 2 hours
30-Day Workmanship Guarantee
All repairs guaranteed in writing
What We Cover
Emergency Boiler Breakdown
No heat or hot water is an emergency in cold weather. We'll diagnose the fault and carry out the repair on the same visit where parts are available — or make the system safe and return with the part within 24 hours.
Pressure Faults (F1, Low Pressure Codes)
Boiler pressure dropping repeatedly signals a leak somewhere in the system — not a faulty gauge. We locate the leak, repair it and repressurise the system correctly.
No Hot Water with Heating Working
When radiators heat but hot water doesn't, the usual cause is a stuck diverter valve or a faulty DHW sensor. We carry diverter valves for most common combi boiler models.
Annual Boiler Service
An annual service — required by most boiler warranties and home insurance policies — checks burner combustion, heat exchanger, flue integrity and safety devices. We issue a full service certificate.
Gas Safety Certificate (CP12)
Required annually for rental properties in London. We carry out the inspection, test all appliances and issue a CP12 certificate. Landlords must provide a copy to tenants within 28 days.
Boiler Replacement Consultation
If the fault cost approaches the boiler's remaining value, we'll tell you honestly. We survey and quote for replacement, and if you proceed, the diagnostic call-out fee is credited against the installation cost.
Pricing Guide
We quote a fixed price for repairs before starting. The diagnostic visit establishes what's wrong; the repair quote follows immediately on site. Parts are charged at trade cost plus 15% handling.
| Job type | Typical cost | Notes |
|---|---|---|
| Emergency boiler diagnosis | £95–£145 | Includes full fault diagnosis and written quote for repair. Part of any repair visit. |
| Annual boiler service | £85–£130 | Includes combustion test, heat exchanger check, safety device test and service certificate. |
| Gas safety certificate (CP12) — landlord | £75–£110 | Includes inspection of all gas appliances. Certificate issued same day. |
| Diverter valve replacement (combi) | £220–£380 | Common cause of no-hot-water faults. Labour includes draining and refilling the system. |
| Pressure vessel / expansion vessel replacement | £180–£320 | Includes removal of failed vessel, new vessel, pressurisation and test. |
All prices include VAT. Parts from manufacturer suppliers at trade prices. We don't carry inflated 'emergency parts premiums' — the same part costs the same whether it's Monday morning or Saturday night.
How It Works
Call and describe the fault
Tell us what your boiler is doing — error code if displayed, whether it's no heat, no hot water or both, and how long the problem has been developing. This helps us bring the right parts.
Gas Safe engineer dispatched
The engineer dispatched will be Gas Safe registered. They'll carry ID and you can verify their Gas Safe status on gassaferegister.co.uk before they start work.
Diagnosis and fixed-price quote
The engineer diagnoses the fault and gives you a fixed price for the repair before touching anything. No pressure — you can get a second opinion before approving the work.
Repair, test and service record
Repair carried out, boiler run up and tested at full load. You receive a written job sheet. If this is a service visit, a signed service record is added to the boiler's history log.
Common Boiler Faults We Fix Across London — and What They Mean
The most common boiler fault we're called to in London is low pressure — usually showing as an F1 error code (Worcester Bosch) or similar on other brands. Homeowners often repressurise the boiler themselves, which is the correct short-term action, but if pressure drops again within weeks it signals a leak in the system — not a boiler fault. The leak might be in a radiator valve, a towel rail connection or a joint in the pipework, and finding it requires pressure-testing the system rather than just refilling the boiler.
The second most common call is 'no hot water but heating works' — particularly in combi boilers. In a combi, a single heat exchanger and diverter valve switch between heating the radiators and heating domestic hot water. When the diverter valve sticks in the heating position, the boiler fires for hot water but the heat goes to the radiators instead. This is often misdiagnosed as a boiler board fault — a new board costs £400–£600 and doesn't fix the actual problem. We check the diverter valve first because it's almost always the cause and the part costs a fraction of the board.
Noisy boilers — kettling sounds, banging on startup, gurgling — are almost always limescale or sludge on the heat exchanger rather than a mechanical fault. In London's hard-water areas this is particularly common. A descale of the heat exchanger (which can be done in situ on most modern boilers) resolves the noise and improves efficiency. If the scale is severe, the heat exchanger may need replacement — but we'll always show you the evidence before recommending that route.
Need help right now?
Gas Safe registered. No call-out fee over 2 hours. All 33 London boroughs.
📞 Call 020 0000 0000Recent Jobs Across London
Fulham, SW6 · Victorian conversion flat
Worcester Bosch 30i showing no hot water — heating radiators working normally
Diverter valve stuck in heating position. Replaced (part on van). Hot water restored in 75 minutes.
£295Hackney, E8 · Victorian terrace
Vaillant ecoTEC Plus losing pressure every 2–3 days — previously repressuried 6 times
Pressure relief valve dripping due to failed expansion vessel. New vessel fitted. Pressure stable 6 weeks later.
£210Bermondsey, SE1 · New-build flat
Ideal Logic+ showing F1 error — resident had been topping up pressure weekly for 3 months
Micro-leak found at radiator valve. Valve replaced. System properly re-pressurised. No recurrence.
£145Stoke Newington, N16 · Victorian semi-detached
Baxi 800 PCB quote of £650 from previous engineer — no heat for 5 days
Re-diagnosis found faulty pump, not PCB. Pump replaced. Boiler working same day. Customer saved £430.
£220Standards & Compliance
Gas Safe
All gas work carried out by Gas Safe Registered engineers (Reg. 123456). We can provide copies of our Gas Safe certificates on request.
Water Regs 1999
All plumbing installations comply with the Water Supply (Water Fittings) Regulations 1999, including notification to the water undertaker for notifiable work.
Building Regs
Domestic plumbing and heating installations comply with Approved Document G (Sanitation, hot water safety) and Approved Document J (heat-producing appliances).
We Cover All 33 London Boroughs
Engineers are stationed across London for fast response in every borough. Click your area for local information.