Mon–Fri 8am–5pm · Emergency call-outs available
info@btdplumbingheating.co.uk 07920 042880
BTD Plumbing & Heating
07920 042880Request a Quote
Detailed copper pipework, cylinder and wall-hung gas boiler mid-repair with system filter and motorised valves
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.

Gas Safe 529962 · Emergency call-outs available · Written quote before work

  • 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 is
Fault-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 for
Homeowners, landlords, letting agents and small businesses across Swindon, Royal Wootton Bassett, Wroughton, Lyneham, Broad Town, Broad Hinton, Marlborough, Yatesbury and Calne.
When you need it
As 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 matters
Diagnosing 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

  1. 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.

  2. Step 2
    On-site fault diagnosis

    Combustion, gas rate, expansion vessel, PCB and controls, sensors, motorised valves | checked in the right order.

  3. 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.

  4. Step 4
    Repair to manufacturer spec

    Genuine or approved parts, correct pressures and torques, combustion re-analysed after the fix.

  5. 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
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.
Zoned central heating manifold with low-loss header and multiple circulator pumps installed by BTD
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
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