Your AI onsite guide

Find the fault before you ring the helpline.

FlintFix puts every boiler's manual, fault codes and structured service data in your pocket, with onsite calculators and an AI assistant that answers from the actual manual, page and all. For UK heating engineers: gas, oil and LPG.

Get FlintFix See what's inside

Free to start. Pro unlocks the AI diagnostic and the deepest service data.

A simple service, the hard way

You've been here.

01No single home for manuals. You Google the model, dig for the right PDF, and hope it's the correct variant.
02Then you scrub 90 pages for one figure, on your phone, in a cold loft.
03Which service-mode sequence is it for this boiler? Every make is different, and nobody remembers them all.
04You need the NTC resistance, the fan speed, the combustion target, and it's buried three sub-menus deep.
05So you ring the manufacturer. Hold music. Customer watching. And the answer doesn't always help.

FlintFix collapses all that into a few taps.

What's inside

The whole job, in your pocket.

01
900+ boilers, one searchManuals across every major maker. Search by model name, GC number or the maker's own code, and get the right one in seconds.
02
Search inside the manualFull-text search within the PDF. Jump straight to the page you need instead of thumbing through ninety of them.
03
Fault codes, decodedWhat the code means, the likely cause, the parts most often replaced, and a steer on the repair cost.
04
Four calculators that earn their placeGas rate (metric and imperial), CO/CO₂ ratio pass or fail, temperature rise (ΔT), and expansion-vessel sizing.
05
Every maker's helpline, one tapThe UK technical line for every manufacturer, built in. Tap to call, no hunting for the number mid-job.
06
Your workbenchFavourites, recently-viewed, and private notes on any model: customer details, parts fitted, settings, kept on your device.

Not just the PDF

The manual, structured.

FlintFix lifts the figures out of the manual and lays them out like instrument readouts, so a service isn't a scrolling exercise. Open any section and the data is already there.

Service mode Combustion targets Gas & burner pressures Oil burner data Technical data NTC sensor tables Spare part numbers Wiring diagrams
Combustion targets that auto-fill the CO/CO₂ calculator with this model's own figures.
Oil, not just gas: nozzle size, pump pressure, smoke number and flue temperature, for the boilers that run on it.
Every value carries its exact manual page, so you can verify it in a tap.
FlintFix Pro

Ask it like you'd ask a senior engineer.

Ask a general fault-finding question, ask about the exact boiler you're on, or tap a fault code and ask how to fix it. Every answer is grounded in that model's manual, cites the page, and takes you straight to it.

YouPressure keeps climbing. Customer's already had the heat exchanger and expansion vessel done. What else?
FlintFix
  1. Filling loop passing. Even slightly, it'll creep the pressure up. Check it's fully closed and not weeping.
  2. Expansion vessel pre-charge not set to the cold-fill pressure, or vessel undersized for the system volume.
  3. Vessel isolation / waterlogging on an external vessel, or a dead-leg on the zone valve holding pressure.

Sources: Greenstar 30i installation manual, p.42 (filling), p.51 (expansion vessel).

Grounded, not guessing

It only answers from the real manual for the model in front of you, and shows you the page. No made-up nonsense.

Always your call

FlintFix is a guide, not a gaffer. Verify against the manual and the data badge. You're still the engineer.

Pricing

Free where it helps. Paid where it pays you back.

Free app
£0forever

Manuals, fault codes, the four calculators and every maker's helpline. Genuinely useful, genuinely free.

Pro
£9.99/ month
or £99 / yearBest value

The manual-grounded AI diagnostic, plus the deeper structured service data.

Get FlintFix Start free. Upgrade to Pro inside the app, whenever it earns its keep.

Built for UK heating engineers.

Gas, oil (OFTEC) and LPG. If you service boilers for a living, FlintFix is built for the way you actually work: fast, one-handed, and grounded in the real manufacturer data.

Be the engineer who walks in already knowing.

Get FlintFix

Opens the app at app.flintfix.com. Free to start.