--- title: "Boiler Fault Diagnosis in Stockport & Greater Manchester | Swainson Gas" description: "Proper boiler fault diagnosis using flue gas analyser and multimeter. Fixed £98 diagnostic fee, written report. Gas Safe #9663. Stockport." lang: en-GB json-ld: | [ { "@context": "https://schema.org", "@type": "Organization", "@id": "/#organization", "name": "Swainson Gas Services Ltd", "alternateName": "Swainson Gas Services", "url": "/", "logo": "/__l5e/assets-v1/2f3afd23-ed83-4d5d-a90b-6d75c9544dc3/swainson-logo.png", "image": "/__l5e/assets-v1/2f3afd23-ed83-4d5d-a90b-6d75c9544dc3/swainson-logo.png", "telephone": "07442 536165", "email": "info@swainsongas.co.uk", "foundingDate": "1986", "founder": { "@type": "Person", "name": "Alan Swainson" }, "address": { "@type": "PostalAddress", "addressLocality": "Stockport", "addressCountry": "GB" }, "sameAs": [ "https://www.facebook.com/people/Swainson-Gas-Services/61563360904402/", "https://www.instagram.com/swainsongas/", "https://x.com/swainsongas" ] }, { "@context": "https://schema.org", "@type": "WebSite", "@id": "/#website", "name": "Swainson Gas Services", "url": "/", "inLanguage": "en-GB", "publisher": { "@id": "/#organization" } }, { "@context": "https://schema.org", "@type": "BreadcrumbList", "itemListElement": [ { "@type": "ListItem", "position": 1, "name": "Home", "item": "/" }, { "@type": "ListItem", "position": 2, "name": "Services", "item": "/services" }, { "@type": "ListItem", "position": 3, "name": "Boiler Fault Diagnosis", "item": "/services/boiler-fault-diagnosis" } ] }, { "@context": "https://schema.org", "@type": "Service", "serviceType": "Boiler Fault Diagnosis", "name": "Boiler Fault Diagnosis", "description": "Proper boiler fault diagnosis using flue gas analyser and multimeter. Fixed £98 diagnostic fee, written report. Gas Safe #9663. Stockport.", "provider": { "@type": "LocalBusiness", "name": "Swainson Gas Services Ltd", "telephone": "07442 536165", "address": { "@type": "PostalAddress", "addressLocality": "Stockport", "addressCountry": "GB" } }, "areaServed": [ "Hazel Grove", "Stockport", "Bramhall", "Cheadle Hulme", "Poynton", "Marple", "High Lane" ], "url": "/services/boiler-fault-diagnosis" }, { "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [ { "@type": "Question", "name": "What does a diagnostic cost?", "acceptedAnswer": { "@type": "Answer", "text": "£98 inc. VAT, fixed fee including flue gas analysis, gas tightness testing, electrical checks and written findings." } }, { "@type": "Question", "name": "How long does it take?", "acceptedAnswer": { "@type": "Answer", "text": "Typically 45–75 minutes for most domestic boilers." } }, { "@type": "Question", "name": "Will you fix it on the day?", "acceptedAnswer": { "@type": "Answer", "text": "If the fault is straightforward and the part is on the van, yes, with your written approval on the quote. Complex or specialist parts are ordered and fitted on a return visit." } }, { "@type": "Question", "name": "What if you can't find the fault?", "acceptedAnswer": { "@type": "Answer", "text": "That's rare, but if it happens we say so and don't dress it up. You still get a written report of what's been eliminated." } }, { "@type": "Question", "name": "Can I get a second opinion after your diagnosis?", "acceptedAnswer": { "@type": "Answer", "text": "Absolutely, the written report is yours to do with as you like. We'd rather you feel confident than pressured." } }, { "@type": "Question", "name": "Do you diagnose all brands?", "acceptedAnswer": { "@type": "Answer", "text": "Worcester, Vaillant, Ideal, Baxi, Main, Potterton and Glow-worm all covered. Most older brands too, ask when you book." } }, { "@type": "Question", "name": "Does the £98 come off the repair price?", "acceptedAnswer": { "@type": "Answer", "text": "The £98 is a diagnostic fee; repair costs are quoted separately. We're straight about the numbers before starting." } }, { "@type": "Question", "name": "How do I book a diagnostic?", "acceptedAnswer": { "@type": "Answer", "text": "Ring 07442 536165, or use the callback form on the contact page." } } ] } ] --- Based in Stockport [info@swainsongas.co.uk](mailto:info@swainsongas.co.uk)Gas Safe registered #9663 Open 7am – 6pm, 7 days [](https://www.facebook.com/people/Swainson-Gas-Services/61563360904402/)[](https://www.instagram.com/swainsongas/)[](https://x.com/swainsongas) [![Swainson Gas Services](/__l5e/assets-v1/2f3afd23-ed83-4d5d-a90b-6d75c9544dc3/swainson-logo.png)](/) [Home](/) [About](/about) [Services](/services) Our services - [Boiler Servicing & Maintenance](/services/boiler-servicing) - [Boiler Repairs & Breakdowns](/services/boiler-repairs) - [Gas Safety Checks](/services/landlord-gas-safety-check) - [Heating Controls & Radiators](/services/thermostat-heating-controls) - [Other Gas Services](/services/gas-fire-servicing) [Areas](/areas) Areas we cover [Hazel Grove](/areas/hazel-grove)[Stockport](/areas/stockport)[Poynton](/areas/poynton)[Bramhall](/areas/bramhall)[Cheadle Hulme](/areas/cheadle-hulme)[Marple](/areas/marple)[High Lane](/areas/high-lane)[Sale](/areas/sale)[Didsbury](/areas/didsbury)[Offerton](/areas/offerton)[Woodley](/areas/woodley)[Bredbury](/areas/bredbury)[Romiley](/areas/romiley)[Davenport](/areas/davenport)[Heaviley](/areas/heaviley)[Gatley](/areas/gatley)[Cheadle](/areas/cheadle)[Disley](/areas/disley)[Handforth](/areas/handforth)[The Heatons](/areas/the-heatons) [Reviews](/reviews) [Contact](/contact) [Call the engineer 07442 536165 ](tel:+447442536165)[Book in now](/contact) ![Flue gas analyser and manometer used to diagnose a boiler fault](/assets/service-fault-diagnosis-DKUqvcYz.jpg) [Home](/)[Services](/services)Boiler Fault Diagnosis Boiler Fault Diagnosis # Boiler Fault Diagnosis in Stockport & Greater Manchester Evidence, Not Guesswork. Error code you don't recognise? Intermittent lock-out? Pressure dropping without a visible leak? A proper diagnostic, flue gas analyser, multimeter, gas tightness test, gets you an answer and a written price. Not a swapped-part-and-hope. [Book a service or repair](/contact) [Call 07442 536165](tel:+447442536165) **5.0** Google (36) Gas Safe #9663 Fixed £98 diagnostic · Written findings Diagnostic £98 inc. VAT Written report Gas Safe registered #9663 Family-run since 1986 12-month workmanship guarantee What we do ## Boiler Fault Diagnosis, done properly. Diagnostic work is where cheap engineers cost you the most. Guess the fault, swap a part, still broken. Guess again, swap another part. Suddenly you've paid £300 in parts and the boiler is still cycling. Proper diagnosis costs £98 and saves that entire experience. What it is A diagnostic visit means: full symptom history from you, visual inspection, flue gas analyser readings, gas tightness test at the meter, multimeter checks on sensors and PCB outputs, and a written summary of what's wrong plus a repair quote. All within the fixed £98 fee. Who it's for Anyone whose boiler is misbehaving in a way they can't explain. Intermittent lock-outs, obscure error codes, mysterious pressure loss, kettling, banging, delayed ignition, hot water going cold mid-shower, anything where the fault isn't blindingly obvious. When you need it Before the fault gets worse. Intermittent faults become permanent ones. Slow pressure loss becomes fast pressure loss. Delayed ignition becomes ignition failure. Diagnose early, spend less overall. Why it matters Because good diagnosis is the difference between one part and three, one visit and three. It's also the difference between a repair and unnecessarily replacing a whole boiler when there was actually one component to swap. Book a service or repair ### Speak directly to the engineer. Diagnostic £98 inc. VAT What happens if it's ignored ## The cost of putting it off. Skipping proper diagnosis and going straight to 'swap the obvious part' is one of the most common false economies in domestic heating. ### Parts churned, fault remains Swap the PCB, swap the fan, swap the sensor, three parts later, still faulty. Diagnosis would have identified the right one immediately. ### Diagnostic-free 'repairs' A repair without diagnosis is a guess. If the guess is wrong, the customer usually foots the bill for the part anyway. ### Unnecessary replacement Boilers get scrapped that had one fixable part. Proper diagnosis is what prevents that. ### Recurring lock-outs Intermittent faults ignored for months become expensive replacements when a controlling part finally gives up entirely. Common mistakes we see - Believing an engineer's diagnosis without a written report, memory is unreliable, notes aren't. - Accepting 'I'll fit the part and see' as diagnosis. - Ignoring a persistent error code because pressing reset makes it go away. Our process ## A clear five-step system. No guessing, no meter-running. Every job follows the same repeatable process, that's how the result stays consistent. 1. 01 ### Symptom history We start with a proper conversation about when, how often, and under what conditions the fault occurs. 2. 02 ### Visual inspection Boiler, flue, controls, condensate, pipework and expansion vessel checked for obvious clues. 3. 03 ### Combustion & gas checks Flue gas analyser, gas tightness test at the meter, gas pressure and flow verified. 4. 04 ### Electrical checks Multimeter tests on sensors, PCB outputs and flame current, this is where most 'random' faults are actually located. 5. 05 ### Written diagnosis & quote You leave the visit with a written summary of what's wrong, a repair quote, and no obligation to proceed on the day. Why it's worth doing ## What you actually get. ### Fixed price up front £98 inc. VAT, no meter running, no surprises. ### Real evidence, not guesses Flue gas analyser and multimeter output isn't opinion. ### Fewer wasted parts Diagnose first, swap once. That's how repairs stay affordable. ### Written findings You keep a copy, useful for second opinions, warranty claims, or landlord records. ### No pressure to proceed You can take the report elsewhere. Most people don't, but the option is yours. ### Fixes rolled in If the fix is quick and the part is on the van, we roll the repair into the visit with your approval. In depth ## The detail that matters. Diagnostic work is the single area where kit and training separate engineers most obviously. Here's what proper diagnosis actually involves. ### Flue gas analysis Calibrated flue gas analyser reads CO, CO2, O2 and combustion ratio at low and high fire. Combustion problems that are invisible from the front panel become obvious in the readings. ### Gas tightness testing A U-gauge or electronic manometer at the meter is the definitive test for gas leaks anywhere on the supply. Non-optional on any proper diagnosis. ### Electrical & sensor checks Multimeter checks on flame current, thermistors, PCB output voltages, and control wiring, this is how you tell a failed sensor from a failed PCB from a wiring fault, without swapping any of them. ### System-side checks Pressure loss diagnosis, expansion vessel pre-charge testing, pump and motorised valve operation, because plenty of 'boiler' faults are actually system faults elsewhere in the house. FAQs ## Questions we hear every week. If you have a question that isn't answered here, ring John directly on 07442 536165. ### What does a diagnostic cost? ### How long does it take? ### Will you fix it on the day? ### What if you can't find the fault? ### Can I get a second opinion after your diagnosis? ### Do you diagnose all brands? ### Does the £98 come off the repair price? ### How do I book a diagnostic? Related services ## Often booked together. [All services](/services) [ Boiler Repairs & Breakdowns Boiler Repairs & Breakdowns Learn more → ](/services/boiler-repairs)[ Boiler Repairs & Breakdowns Emergency Boiler Callouts Learn more → ](/services/emergency-boiler-callouts)[ Boiler Servicing & Maintenance Boiler Servicing Learn more → ](/services/boiler-servicing)[ Boiler Servicing & Maintenance Central Heating Maintenance Contracts Learn more → ](/services/central-heating-maintenance-contract) ![Swainson Gas Services vehicles ready for calls across Stockport and Hazel Grove](/__l5e/assets-v1/160943dc-12df-4f98-9e74-b100ef4b83cc/swainson-gas-services-service-vehicles-fleet.jpg) Ready when you are ## Odd fault? Book a proper diagnostic, not a parts guess. £98 fixed, written findings, and the engineer who'll do the repair too. [Book a service or repair](/contact) [07442 536165](tel:+447442536165) Gas Safe #9663 · 12-month workmanship guarantee · Card on the job ![Swainson Gas Services](/__l5e/assets-v1/2f3afd23-ed83-4d5d-a90b-6d75c9544dc3/swainson-logo.png) Swainson Gas Services Family run · Est. 1986 Stockport's trusted boiler repair, servicing and gas safety specialists. Nearly 40 years on the tools, one engineer, one standard. Gas Safe Registered Registration No. 9663 Services - [Boiler Repairs](/services/boiler-repairs) - [Boiler Servicing](/services/boiler-servicing) - [Landlord Gas Safety Check](/services/landlord-gas-safety-check) - [Emergency Boiler Callouts](/services/emergency-boiler-callouts) - [Central Heating Maintenance](/services/central-heating-maintenance-contract) Areas covered - [Hazel Grove](/areas/hazel-grove) - [Stockport](/areas/stockport) - [Poynton](/areas/poynton) - [Bramhall](/areas/bramhall) - [Cheadle Hulme](/areas/cheadle-hulme) - [Marple](/areas/marple) - [High Lane](/areas/high-lane) - [Sale](/areas/sale) - [Didsbury](/areas/didsbury) - [Offerton](/areas/offerton) - [Woodley](/areas/woodley) - [Bredbury](/areas/bredbury) - [Romiley](/areas/romiley) - [Davenport](/areas/davenport) - [Heaviley](/areas/heaviley) - [Gatley](/areas/gatley) - [Cheadle](/areas/cheadle) - [Disley](/areas/disley) - [Handforth](/areas/handforth) - [The Heatons](/areas/the-heatons) [See all areas & services →](/areas-we-cover) Contact - [07442 536165](tel:+447442536165) - [info@swainsongas.co.uk](mailto:info@swainsongas.co.uk) - Based in Stockport - 7 days a week, 7 AM – 6 PM [](https://www.facebook.com/people/Swainson-Gas-Services/61563360904402/)[](https://www.instagram.com/swainsongas/)[](https://x.com/swainsongas) © 2026 Swainson Gas Services Ltd. 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