Open 24/7 · 7 days a week info@btdplumbingheating.co.uk 07920 042880 HomeAboutServices Service Areas Our WorkReviewsContact07920 042880 Gas Safe boiler repairs # Gas boiler repairsdiagnosed properly, quoted honestly Boiler locked out, losing pressure, running noisy or refusing to heat the radiators, diagnosed by a Gas Safe registered engineer with eighteen years on the tools, priced in writing, fixed once. Request a Free Quote 07920 042880 Gas Safe 529962 · Emergency call-outs available · Written quote before work - Home - Services - Gas Boiler Repairs - 529962 Gas Safe reg. - 6073839 Engineer reg. - 18 years Experience - Available Emergency call-outs - Free Quote before work Overview ## A straight explanation of what we do, and why it matters A gas boiler that won't fire, keeps locking out or leaves you with cold radiators isn't just an inconvenience; it's a heating and hot-water system out of action. We diagnose properly, quote before work and fix once. Back to home What it isFault-finding and repair on gas boilers, controls, motorised valves, expansion vessels, PRVs, diverter valves, gas hobs and cookers. Every UK brand and every layout, combi, system, regular. Who it's forHomeowners, landlords, letting agents and small businesses across Swindon, Royal Wootton Bassett, Wroughton, Lyneham, Broad Town, Broad Hinton, Marlborough, Yatesbury and Calne. When you need itAs soon as the fault appears. Repeated lockouts, pressure that won't hold, radiators cold at the top or the bottom, hot water that runs cold, noises you didn't used to have, all fixable, all worse the longer they're left. Why professional mattersDiagnosing gas faults is a discipline: correct order, correct instruments, correct pressures. Done properly it's fast. Done as guesswork it's expensive. The cost of leaving it ## What happens when it's ignored The most expensive boiler repair is the wrong one, done twice. Risks & escalations - Repeated topping-up of a leaking system waterlogs the expansion vessel and drives up the PRV, one fault becomes three. - Ignored 'kettling' noises usually mean a fouled heat exchanger. Left long enough, it needs replacing. - Boilers running with a poor combustion or a partially blocked flue produce carbon monoxide. Not theoretical, real. - A boiler that keeps locking out on flame failure isn't 'being annoying'; it's telling you something is wrong. - DIY repairs on gas appliances are illegal without Gas Safe registration and, more importantly, dangerous. Common mistakes - Hitting the reset button five times in a row and assuming that's a fix. - Topping the pressure back up every week without finding out where the water is going. - Using non-approved parts. Warranties don't survive it and neither, often, does the boiler. - Calling anyone other than a Gas Safe registered engineer for a gas appliance. Ring us, describe what's happening, and we'll bring the parts the fault pattern suggests. Most gas boiler repairs are finished in one visit. Our process ## A clear, five-step system, no surprises - Step 1 Symptom triage on the phone Brand, model, error code if there is one, what happens on reset, any noises or leaks | half the diagnosis starts here. - Step 2 On-site fault diagnosis Combustion, gas rate, expansion vessel, PCB and controls, sensors, motorised valves | checked in the right order. - Step 3 Written quote before work Once we know the fault, you get a clear price for the fix | parts and labour | before we do it. - Step 4 Repair to manufacturer spec Genuine or approved parts, correct pressures and torques, combustion re-analysed after the fix. - Step 5 Test, sign-off and guarantee Full firing sequence, safety devices, DHW performance and radiator temperatures verified. Any issue with our workmanship is put right personally. The benefits ## Concrete outcomes, not vague promises Gas Safe by law Any repair to a gas appliance must be carried out by a Gas Safe registered engineer. We are | reg 529962. Diagnosis, not guesswork Combustion analyser, manometer, multimeter and eighteen years of pattern recognition. Priced in writing first You approve the price before any spanner turns. No surprise invoices. Emergency call-outs Available when you need us | priority for no-heat, no-hot-water and vulnerable-occupant situations. Fixed once Underlying cause found, not just the symptom that tripped the boiler out. Genuine parts PCBs, diverter valves, expansion vessels and sensors to the boiler manufacturer's specification. In detail ## The technical stuff, explained straight Where the theory meets the van. Materials, methods, brand differences and the specific situations we deal with week in, week out across Wiltshire. ### Common gas boiler faults and what they usually mean F22 / low pressure: pressure loss somewhere, expansion vessel, PRV or system leak. F1 / lockout on ignition: gas supply, ignition leads, flame-sensing electrode or PCB. Noisy 'kettling': scale or sludge on heat exchanger, poor circulation, or fan/pump issue. Radiators cold at top: air in the system, needs bleeding and inhibitor check. Radiators cold at bottom: sludge, flush and inhibitor. Hot water runs cold: diverter valve stuck, plate heat exchanger scaled, DHW flow sensor. Boiler cycles on and off rapidly: short cycling, usually thermostat, controls or oversizing rather than the boiler itself. Each has a shortlist and a diagnostic order. ### Repairs by boiler brand Worcester Bosch: diverter valves, PRVs, condensate traps, low-water pressure faults. Vaillant: expansion vessels, PCB firmware, diverter valve behaviour. Ideal Logic and Vogue: ignition leads, PCB and fan pressure switches. Baxi and Potterton: diverter valves, fan assemblies, PCBs. Alpha and Glow-Worm: pumps, expansion vessels, sensors. Viessmann: high-quality controls but PCB replacements should always be done properly. We hold service parts for regulars and can order specialist parts quickly when needed. ### Pressure loss and expansion vessels The single most common repeated boiler issue we see is pressure that won't hold. Rarely a boiler leak, usually one of: a failed expansion vessel that no longer holds its air charge, a weeping PRV that's now stuck open, or a small radiator or pipework leak somewhere on the system. Repeat topping-up hides the fault and adds fresh, oxygenated, unhibited water that then sludges up the radiators. We pressure-test, recharge or replace the vessel, and repair the source, properly. ### When repair stops making sense A boiler over 12–15 years old with a heat exchanger failure, PCB failure or major casing corrosion is often at the point where a new boiler is more cost-effective than the repair. We'll always give you an honest side-by-side, repair quote and replacement quote, so you can decide with real numbers, not sales pressure. ### Gas hobs, cookers and other gas appliances Beyond boilers we also carry out repairs on gas hobs and cookers, replacing igniters, gas taps, thermocouples and burners, checking for leaks and confirming safe operation. Same Gas Safe registration, same approach: diagnose, quote, fix once. FAQs ## The questions we're asked most Can't see yours? Give us a ring; we don't do sales scripts. Call 07920 042880 Do you charge a call-out fee?We don't run a flat call-out or fixed-price structure. What we do promise is a straight answer on the phone and a written quote before any work is carried out. How quickly can you attend? Can you repair my brand of boiler? Is there a guarantee on the work? Is a boiler that keeps locking out dangerous? Will you fit non-manufacturer parts to save money? Should I repair or replace my boiler? Do you work on landlord properties? Do you cover my area? Can you service the boiler at the same visit? Free written quote · no pressure ## Gas boiler playing up? Get a real diagnosis today. Tell us what's happening and we'll bring the right parts. Free written quote before any work is carried out. - Gas Safe 529962 - OFTEC C11108 - 18 years' experience 07920 042880Request a Free Quote Related services ## Often booked alongside Gas Boiler Repairs All services Gas Boiler Servicing Gas Boiler Installation Central Heating Systems Oil-fired heating specialists and fully qualified gas engineers, serving Broad Town and rural Wiltshire since 2007. Leave a review ### Services - Oil Boiler Servicing - Oil Boiler Repairs - Oil Boiler Installation - Gas Boiler Servicing - Gas Boiler Repairs - Gas Boiler Installation - Water Softener Installation - Central Heating Systems - All services → ### Service Areas - Broad Town - Royal Wootton Bassett - Broad Hinton - Lyneham - Wroughton - Marlborough - Yatesbury - Swindon - Calne ### Contact - 07920 042880 - info@btdplumbingheating.co.uk - Pye Lane, Broad Town, Swindon, SN4 7RRGas Safe Reg. 529962 OFTEC Reg. C11108 · Tech. 28212 City & Guilds Qualified Grant UK G1 Approved Installer © 2026 BTD Plumbing & Heating. All rights reserved. AboutContactPrivacyTermsCookiesOpen 24/7 · Mon–Sun Call NowRequest Quote