Gas boiler diagnostics and repair with replacement PCB and diverter valve
Boiler Repairs · Witney, Oxford & Oxfordshire

Boiler Repairs & Breakdownsin Witney, Oxford& Oxfordshire.

Locked-out combi, no hot water, weeping seal, fault code you don't understand? Gas Safe registered diagnostics, fixed price in writing, and the parts on the van to finish the vast majority of repairs on the first visit.

Priority breakdown responseFixed-price repair, quoted firstVaillant & Worcester approved
Gas Safe Registered
Every gas engineer individually qualified
Priority Emergency Response
Emergencies prioritised within working hours
Vaillant Approved
Genuine parts & diagnostics
Worcester Approved
Manufacturer register
5.0 on Google
Reviewed by Oxfordshire homeowners
What we do

Boiler Repairs, explained properly.

What it is

Boiler repair covers everything from a simple pressure top-up and reset to full component replacement (PCBs, fans, diverter valves, expansion vessels, gas valves, heat exchangers), carried out under Gas Safe regulations.

Who it's for

Any Oxfordshire homeowner or landlord with a locked-out, leaking or under-performing gas boiler. Combi, system and regular. All major brands.

When you need it

The moment the boiler drops out, throws a fault code, leaks visibly, loses pressure repeatedly, or fails to reach temperature. Small faults become expensive fast if ignored.

Why a qualified team matters

Gas work is legally restricted to Gas Safe registered engineers. Beyond the law, a wrong diagnosis on a modern boiler wastes hundreds, a new PCB is not the answer to a £30 sensor. Manufacturer-approved diagnostics find the real fault the first time.

What happens if it's left

The cost of ignoring it.

A ignored boiler fault is the reason for most 'sudden' January breakdowns, the warning signs were there in October.

Bigger repair bill

A failing pump run hot for weeks can burn out the motor, destroy the diverter valve and cook the PCB. What was a £180 pump becomes an £800 rebuild.

No heat in cold weather

Ignored fault codes tend to escalate to full lockout at the worst possible time. Engineer availability collapses in a cold snap.

Safety hazards

Combustion, flue and CO risks live inside a poorly maintained boiler. Only a Gas Safe engineer can lawfully diagnose and sign off.

Voided warranty

Unauthorised or DIY repairs void manufacturer cover, even if the fix seems successful, the warranty is gone.

Common mistakes we see

  • Repeatedly topping up pressure to mask a hidden leak in the system
  • Resetting a fault code over and over instead of investigating it
  • Booking a general handyman for a boiler (illegal, must be Gas Safe)
  • Fitting a cheap universal part instead of manufacturer-approved
  • Ignoring gurgling, kettling or banging sounds, all early warnings
Our process

How we run the job.

  1. 01

    Phone triage

    We ask the fault code, the symptoms and the boiler model. Some issues resolve on the phone. Everything else gets the earliest booking we can offer.

  2. 02

    On-site diagnostics

    Case off, manufacturer-approved diagnostics, live readings, gas rate and combustion checks. We find the real fault, not the visible one.

  3. 03

    Fixed-price repair quote

    Before ordering parts or spending your money, you get a fixed price. We'll also tell you honestly if repair no longer makes sense vs. replacement.

  4. 04

    Repair on visit one where possible

    Common failure parts on the van, sensors, PRVs, expansion vessels, diverter cartridges, diaphragms. Most breakdowns finish on the first visit.

  5. 05

    Test & document

    Combustion tested, benchmark logbook updated, warranty on parts confirmed. Every repair is documented for future service history.

Benefits

What you actually get.

One visit, most of the time

Stocked vans and correct first-time diagnostics mean the majority of breakdowns are fixed on the first visit.

Honest repair-vs-replace advice

If your boiler is beyond economic repair, we'll say so and quote a replacement, not sell you a bandage that fails again.

Manufacturer warranty passed on

Every part we fit carries its own manufacturer warranty, registered and passed straight on to you.

Approved diagnostics

Vaillant and Worcester approved means we use manufacturer diagnostic kit and genuine parts.

Transparent pricing

Fixed prices in writing before work starts. No hourly meter, no surprise bills.

Same team for service & repair

Continuity, the engineer who repairs today can service next year and knows the boiler's history.

The detail

Depth, not filler.

Modern gas boilers fail in predictable patterns. Here's what we see most often across Oxfordshire homes.

Pressure loss & PRV failures

Constant pressure drops usually mean a hidden system leak, a failed expansion vessel, or a passing PRV. We isolate the cause instead of just topping up.

No hot water, heating fine

Classic diverter valve or plate heat exchanger fault on a combi. Replaceable parts, priced clearly.

No heating, hot water fine

Often a stuck motorised valve, dead pump, or programmer fault. Diagnosed with meter readings, not guesswork.

Fault codes & lockouts

F22, F28, F75, EA, E133, we know what they mean on Vaillant, Worcester, Ideal, Baxi and more, and what actually causes them.

Kettling & banging

Almost always limescale in the heat exchanger or magnetite build-up in the system. A full system clean usually resolves it, see Central Heating.

Fan, PCB & sensor failures

The 'expensive' repairs. We only replace what's actually failed, approved diagnostics stop unnecessary PCB swaps.

Condensate freeze in winter

Common Oxfordshire winter call: a lagged condensate line stops it happening. We can fit protection as part of the visit.

When repair no longer makes sense

If you're on your third major repair on a 12+ year-old boiler, replacement is usually cheaper over 2 years than continuing to patch. We'll show you the numbers honestly.

FAQs

Straight answers.

How much does a boiler repair cost?

Diagnosis and small repairs typically fall in the £120–£280 range. Larger component replacements (PCB, fan, gas valve) are priced individually and always quoted in writing before work starts.

How fast can you come out?

For no-heat and no-hot-water calls we prioritise the earliest available slot during working hours across Witney, Oxford, Carterton and surrounding areas.

Do you fix all brands?

Yes, Vaillant, Worcester Bosch, Ideal, Baxi, Alpha, Glow-worm, Viessmann and others. We're specifically approved on Vaillant and Worcester Bosch.

What's a call-out fee?

We don't do 'call-out + then extras' pricing. On arrival we diagnose the fault and give you a fixed price for the repair. If you decline, you pay a fair diagnostic fee only.

Is my boiler worth repairing?

Depends on age, brand, and cost of repair vs. new. Broadly: under 8 years old, repair almost always makes sense. Over 12 years with a major fault, it often doesn't. We'll give you the maths.

Is the replacement part covered?

Yes, every replacement part carries its own manufacturer warranty, which we register and pass on to you.

Will a repair void my warranty?

Only unauthorised work voids warranty. Gas Safe repair by an approved installer with correct parts and documentation keeps warranty intact.

Can you also service it while you're there?

Often yes, if it makes sense to combine the visit we can carry out the service on the day. We'll price it before we start.

Ready when you are

Get a fixed-price quote for boiler repairs in Witney, Oxford.

Free, no-obligation quote in writing. Gas Safe, MCS certified where relevant, fully insured to £5m. Local team, real engineers, no call centres.

Gas Safe RegisteredMCS Certified£5m Public Liability
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