6.1 million UK heating callouts every year are for things a homeowner could fix themselves — bleeding a radiator, repressurising a boiler, thawing a frozen pipe. But they don't know that. Point your phone at your heating system and HeatScope tells you what's wrong in 2 minutes. £4.99/mo instead of £300 for "it just needed bleeding."
The average UK boiler callout costs £250-£350. 40% of those visits — over 6 million a year — are for faults any competent adult could fix with a spanner and 5 minutes of guidance. But homeowners don't know that, so they pay. Every. Single. Time.
A radiator that's cold at the top just needs bleeding with a radiator key — a 60-second fix that costs £1.50 for the key. But when your house is freezing and you don't know what to do, you call an engineer. They bleed it, charge £85 callout + £65 labour + VAT, and you've paid £180 for something YouTube could have taught you in 2 minutes.
Boilers break on Friday evening with suspicious consistency. Emergency weekend callout rates are £350+. You're sitting in a cold house for 48 hours because you don't know if the problem is serious or if you just need to press the reset button and top up the pressure to 1.5 bar.
Most homeowners resort to Googling symptoms: "boiler making loud banging noise." Results range from "it's going to explode" to "add a magnetic filter" to "it's normal." No personalised assessment. No confidence score. Just forums from 2014 suggesting you bleed pump A while holding valve B — with zero visual guidance.
British Gas reports that 35-40% of their HomeCare callouts result in "no fault found" or "user error" — the boiler was fine, the thermostat was on the wrong setting, or the timer was on holiday mode. Thousands of vans dispatched for problems that a 2-minute diagnostic flow would have resolved. HeatScope eliminates that waste entirely.
Point your camera at your boiler, pump, or radiators. HeatScope's AR overlay labels every component and walks you through a diagnostic flow. In 8-12 questions, you know exactly what's wrong — and whether you can fix it yourself or genuinely need an engineer.
Open the app, point your camera at your boiler. Computer vision identifies the make/model and overlays AR labels on every component: pump, diverter valve, expansion vessel, pressure gauge, condensate pipe.
The app asks you smart diagnostic questions based on what it sees: "Is the pressure gauge between 1-1.5 bar?" → "Touch the pump — is it hot and vibrating?" → "Check the radiator in the coldest room."
After 8-12 questions: "87% confidence — Airlock in radiator 3 (bedroom)." You get a step-by-step fix guide with AR overlay arrows showing exactly which valve to turn with your radiator key. Video guide included.
DIY-safe fixes get video walkthroughs. If the problem genuinely needs a Gas Safe engineer (gas valve, PCB, ignition unit), the app flags it clearly and connects you to a vetted local engineer — no unnecessary callout fees.
Trained on 50,000+ labelled images of boilers, pumps, valves, and heating components. Identifies makes and models to pull up manufacturer-specific diagnostic trees. Works on boilers from Worcester Bosch, Vaillant, Baxi, Ideal, Viessmann, and Glow-worm.
A branching diagnostic tree covering the top 12 UK heating faults. Each answer constrains the possible causes. After 8-12 questions, the tree converges on a diagnosis with a percentage confidence score. Below 70% confidence, it recommends an engineer — no false confidence that gets someone hurt.
For safe fixes (bleeding radiators, repressurising, resetting, thawing condensate pipes), the AR overlay shows exactly which valve to turn, which direction, and how much. Arrows highlight the bleed screw. A looping animation shows the motion. 90% of users complete the fix on first attempt.
HeatScope draws a hard line at gas and electrical work. If the diagnosis points to the gas valve, PCB, ignition electrode, or flue — the app locks out DIY guidance and only shows "Gas Safe Engineer Required." No liability grey areas. No "try turning this gas fitting" disasters.
The app builds a history of your system: pressure trends, radiator balance, seasonal efficiency. Predicts failures before they happen — "Your pressure is dropping 0.1 bar/week. Likely a slow leak. Fix it now before it strands you on a cold Sunday."
When a fix needs a pro, HeatScope connects you to a vetted local Gas Safe engineer with the diagnosis pre-shared. The engineer arrives knowing exactly what's wrong and what parts to bring. No "I'll need to order that part — that'll be another callout fee." 12% marketplace commission per booking.
This isn't a niche problem. 23 million UK homes have gas central heating. 15.3 million heating callouts happen every year. 40% of them — 6.1 million — could be solved by a homeowner with proper guidance.
Total addressable market: every UK home with a gas boiler. 95% of UK homes have central heating; 85% of those are gas-fired. Installation base grows by 1.6M new boilers every year.
The average UK household calls a heating engineer once every 18 months. Callout rates spike 62% in December-February. Weekend emergency rates are £350+.
40% of callouts are for: bleeding radiators, repressurising, resetting after lockout, thawing condensate pipes, adjusting thermostats/timers, clearing airlocks. Average cost per unnecessary callout: £250.
Conservative Year 3 target: 42,000 subscribers (1.3% of DIY-fixable callouts). Average revenue per user: £49.68/year. 12% of users book through the engineer marketplace.
| Metric | Year 1 | Year 2 | Year 3 |
|---|---|---|---|
| Subscribers | 8,500 | 24,000 | 42,000 |
| Subscription Revenue | £340K | £960K | £1.68M |
| Engineer Marketplace Fees | £48K | £175K | £340K |
| B2B White-Label Revenue | £0 | £40K | £120K |
| Total Revenue | £388K | £1.18M | £2.14M |
| Operating Costs | £290K | £580K | £890K |
| Net Profit | £98K | £595K | £1.25M |
| Profit Margin | 25% | 50% | 58% |
8 weeks development. Covers: iOS + Android app (React Native), computer vision model training (TensorFlow/CoreML), diagnostic tree engine, basic AR overlay (ARKit/ARCore), engineer marketplace API, admin dashboard. Team: 1 senior full-stack, 1 ML engineer, 1 UX designer, 1 part-time heating engineer (domain expert).
At 8,500 subscribers (£340K ARR), operating costs are covered. Marketing spend scales with revenue. CAC target: £12 per subscriber (app store ads, heating forums, plumber referral programme). LTV: £57 per subscriber (14-month average retention). LTV:CAC ratio: 4.75:1.
License HeatScope to home emergency insurers (British Gas, HomeServe, Domestic & General). They pay £2 per callout avoided when their customers use HeatScope instead of requesting an engineer. 30,000 avoided callouts in Year 2 = £60K B2B revenue. Scales to £250K+ by Year 4.
UK-first, then Germany (20M gas boilers), France (12M), Netherlands (7M). US expansion via heat pump diagnostics — the IRA is driving millions of heat pump installs with zero consumer diagnostic tools. Same AR tech, different component library.
Actually, the opposite. The 40% of callouts that HeatScope eliminates are the ones engineers hate — driving across town to bleed a radiator, reset a boiler, or explain a thermostat to someone who didn't read the manual. Those jobs are low-margin and soul-destroying. The engineer marketplace sends them pre-qualified jobs they actually want: real faults they can fix with parts in hand, at full rate, with no wasted trips. Many engineers will promote HeatScope to their customers — it filters out the time-wasters and fills their calendar with profitable work.
HeatScope's diagnostic engine has a hard boundary: any fault requiring gas work, electrical work, or flue access immediately flags "Gas Safe Engineer Required" and locks out all DIY guidance. The AR guides only cover: bleeding radiators, repressurising boilers (water side only), thawing external condensate pipes, resetting boilers, adjusting thermostats/timers, and identifying components. None of these involve breaking the gas seal or accessing the combustion chamber. The app carries professional indemnity insurance. Every fix guide ends with "If you're unsure at any point, stop and call a professional."
HeatScope's CV model is trained on the top 15 UK boiler brands (98% market coverage). For the first-time setup, users select their boiler brand from a list, then point their camera — the model identifies the specific model variant by recognising the control panel layout, pressure gauge position, and component arrangement. New models are added continuously via crowd-sourced labelling — users can submit photos of unrecognised boilers, which get added to the training pipeline within 72 hours.
Google gives you text. HeatScope gives you a personalised, interactive diagnostic that sees your actual boiler. The difference is like WebMD vs an actual doctor — except in this case, the "doctor" is a decision tree written by heating engineers with 40+ years of combined experience, and the 8-12 question flow narrows 200+ possible faults down to 1-3 with confidence scoring. YouTube might help if you already know the part is called a "diverter valve" — HeatScope tells you what the part is called, where it is on your specific boiler, and whether the fault is in it.
The business case is done. The market is validated. The £1.53 billion problem is real and the competitive moat — AR + CV + domain-specific diagnostic trees — is deep. Buy the full plan or talk to Sovael about building your MVP.
The £49 business case includes: full 38-page plan, competitor analysis, CV model training spec, diagnostic tree diagrams, financial model (Excel), go-to-market timeline, and technical architecture doc.