Mon–Fri 8am–5pm · Emergency call-outs available
info@btdplumbingheating.co.uk 07920 042880
BTD Plumbing & Heating
07920 042880Request a Quote
Oil boiler burner assembly with pressure gauge and diagnostic tools during a repair
Off-grid heating fixed fast

Oil boiler repairsdiagnosed properly, fixed once

Lockouts, no-fires, sooting, smoke, oil leaks or a boiler that just won't hold pressure, diagnosed by an OFTEC-registered oil specialist, priced clearly, fixed the first time.

OFTEC C11108 · Emergency call-outs available · Free written quote before work

  • C11108
    OFTEC business
  • 28212
    Technician reg.
  • 18 years
    Experience
  • Available
    Emergency call-outs
  • Free
    Quote before work
Overview

A straight explanation of what we do, and why it matters

When an oil boiler goes down in a Wiltshire winter it's more than an inconvenience, off-grid homes have no gas back-up and immersion-only hot water gets old fast. We diagnose properly, quote in writing and fix once.

Back to home
What it is
Fault-finding and repair for oil-fired boilers, burners, oil lines, tanks and system controls. Everything from a repeat lockout on a Worcester Danesmoor to a full Grant Vortex burner rebuild, a leaking Firebird flexi, a Trianco electrode set or a Warmflow that won't hold pressure.
Who it's for
Homeowners, landlords, farms and businesses across Broad Town, Royal Wootton Bassett, Marlborough, Calne, Swindon and the surrounding rural villages, any UK oil boiler brand, any age, whether we installed it or not.
When you need it
As soon as the fault appears. A boiler that's locking out, smoking, running noisy, smelling of oil or leaving soot around the case is telling you something. The longer it runs like that, the more damage builds up and the bigger the eventual bill.
Why professional matters
Oil boiler faults are rarely random. Nine out of ten sit in a small handful of causes, nozzle, electrodes, photocell, pump pressure, fuel supply, controls, and the right diagnostic order finds them fast. Guesswork replaces parts you didn't need and misses the ones you did.
The cost of leaving it

What happens when it's ignored

A dead oil boiler on a Friday evening in January isn't the moment to be phoning round asking who knows oil.

Risks & escalations
  • Repeated lockouts almost always leave unburnt fuel in the combustion chamber, a genuine fire risk on restart.
  • Running with a partial blockage sooties up the heat exchanger fast, cutting efficiency and eventually cracking cast-iron sections.
  • Leaking oil lines contaminate soil and, near a drain, watercourses, a legal problem as well as an expensive clean-up.
  • No heat means frozen pipework in a cold spell. Burst pipes cost multiples of a boiler repair.
  • A misdiagnosed fault often means paying twice, once for the wrong part, once for the right one.
Common mistakes
  • Repeatedly resetting a boiler that keeps locking out; it's not a nuisance, it's a diagnostic.
  • Topping up pressure without finding out where it's going.
  • Calling a gas engineer to look at an oil boiler. Different fuel, different regulator, different rules.
  • Ignoring a strong oil smell around the boiler or tank. Small drips become big bills.

Ring us first, describe the symptoms honestly, and we'll bring the parts that fit that fault profile. Most repairs are done in one visit.

Our process

A clear, five-step system, no surprises

  1. Step 1
    Symptom triage on the phone

    Brand, model, age, what happens when you press reset, any noises, smells or sooting. Half the diagnosis often starts here.

  2. Step 2
    On-site fault diagnosis

    Electrical checks, fuel supply pressure, combustion analysis and visual strip of the burner as needed. No guessing.

  3. Step 3
    Written quote before work

    Once we know what's wrong, you get a clear price for the fix | parts and labour | before we do it.

  4. Step 4
    Repair to manufacturer spec

    Genuine or OFTEC-approved parts, tightened to spec, seals renewed, combustion re-tested with an analyser.

  5. Step 5
    Test, sign-off and guarantee

    Full firing sequence tested, safety devices verified, report handed over. Any issue with our workmanship is put right personally.

The benefits

Concrete outcomes, not vague promises

Right diagnosis, first time

Eighteen years of oil work means the shortlist of likely causes is short. Less time on your job, less on your bill.

Repaired to OFTEC standard

Combustion re-analysed after every repair | not just 'it fired up, off I go'.

Fast on urgent no-heats

Emergency call-outs available. We prioritise no-heat, vulnerable-occupant and safety-critical faults.

Priced honestly, in writing

You approve the price before any spanner turns. No surprise invoices.

Fixed once, not repeatedly

We find the underlying cause, not just the symptom that tripped the boiler out.

Genuine parts

Nozzles, pumps, photocells and electrodes to manufacturer spec | no bargain-bin substitutes.

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.

The most common oil boiler faults | and what they actually mean

Lockout on start-up: usually a worn nozzle, dirty photocell or a fuel supply issue. Rumbling or delayed ignition: nozzle sizing, air setting or an electrode gap out of spec. Sooting inside the boiler casing: combustion running rich, often nozzle, air damper or a fuel pump losing pressure. Kettling and expansion noise: heat exchanger fouled, poor circulation or system water quality. Pressure won't hold: expansion vessel gone flat, PRV weeping, hidden leak on system pipework. Boiler fires then stops on flame failure: photocell, electrodes, transformer or fuel supply. We work through them in diagnostic order, verify with instruments and fix the cause, not the symptom.

Brand-specific know-how

Worcester Bosch Greenstar Danesmoor: sensitive to fuel filter condition and pump pressure. Grant Vortex: baffle sets and combustion chamber liners matter; we carry spares. Firebird Enviroblue: flexi hoses and burner gaskets on the shortlist. Warmflow: photocell and lockout module frequently misdiagnosed. Trianco TRO/TRG: electrode set and combustion head fouling. Mistral, Boulter Camray, HRM Wallstar and Riello-burnered models, all regulars on the van.

Oil supply | the fault that's rarely 'the boiler'

An enormous share of 'boiler' callouts turn out to be fuel supply. Water in the tank, sludge across the take-off, a partially blocked filter, a fire-valve that's dropped shut, a flexi hose split at the burner. We check the whole supply, tank, isolation, filter, fire-valve, remote sensor and flexis, as part of every diagnosis, because replacing a nozzle without fixing bad fuel just brings you back next week.

Sealed system faults on oil boilers

Most modern oil boilers run on sealed systems, and repeat pressure loss is the most common non-combustion fault we see. Causes: failed expansion vessel (needs recharging or replacing), passing PRV, hidden radiator or pipework leak, cracked heat exchanger, or air being drawn in through auto-air vents. We pressure-test properly rather than just topping you up and hoping.

When repair stops being sensible

If a boiler is over fifteen years old, off-parts-support, or facing a heat-exchanger crack or major casting failure, we'll say so and give you honest numbers for both routes, repair vs replacement, so you can decide on facts, not sales pressure.

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, pricing depends on the job. 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

Boiler down or misbehaving? Get a real answer today.

Tell us the symptoms and we'll bring the parts to match. Free quote before any work, no scripts, no scare tactics.

  • Gas Safe 529962
  • OFTEC C11108
  • 18 years' experience
07920 042880Request a Free Quote
Related services

Often booked alongside Oil Boiler Repairs

All services
Oil Boiler Servicing
Oil Boiler Installation
Central Heating Systems
Call NowRequest Quote