Why we do this

Most of what we get given is written for someone who already knows the answer. A fault code and a table. Nothing that tells you what is actually going on inside the machine.

So the test here is simple. Someone who doesn't do F-Gas at all should be able to read a screen and go "right, that makes sense, I know what's wrong now". If it can't be said that plainly, it isn't finished yet.

No fluff. No jargon for the sake of it.

The physics doesn't change between makes. Pressure and temperature behave the same in a Mitsubishi as they do in a Daikin. Only the badge and the fault code are different.

So we teach the physics, not the badge. Get your head round what is happening in the circuit and it carries over to the next machine, and the one after that. That understanding stays with you. The app is just where it's written down.

It's also why anything we build goes across every make we cover, not whichever one was easiest.

Words only get you so far. There's a picture of the circuit with the four states coloured in, and your own readings plotted on a chart you can actually look at.

Seeing where your numbers sit does more in five seconds than a page of text does in five minutes. And you remember it next time.

A label and a couple of words is all that's on the page. Anything longer sits behind an info button.

Twenty years in and you'll never tap it. Six months in and there's proper plain-English teaching waiting there. You pick how deep you go, not me.

Figures come out of manufacturer manuals and databooks, model by model. Where a figure isn't published, the app says so instead of making one up.

Where two official documents disagree, we take the one that claims less. I'd rather the app said less and was right.

This isn't meant to be a one-stop shop that does everything badly. It's meant to be your business headquarters in your pocket. Diagnostics, the paperwork, your records, all in the place you already are, which is on site with a phone.

It's not a big corporate outfit. It's engineers in the field testing it and telling me straight when something is rubbish, and that's what decides what gets built next.

If you use it and something annoys you, tell me. That's genuinely how most of it has got better so far.