A water heater occupies one corner of the cramped airing cupboard, next to a slightly damp mop leaning against the wall.

The water heater is a plain white that appears yellowish in the weak light. Rust streaks shows through its enameling. A pilot light is an ethereal blue glimmer within its confines. You shudder to think of the gas bill.

Check. From the beginning of your career to this point, you’ve inspected exactly seven hundred and nineteen airing cupboards, with no end in sight. After the first hundred, you’ve figured out that it was impossible to map a return route to those cupboards, and could only hope you didn’t inspect the same one twice. There’d be hell from above.

The water heater bothers you, though. A forty gallon job, quite possibly the cheapest one on the market, and it’s the only water heater you’ve seen. And you’ve been all over the house.

You’re happy showering isn’t exactly one of your favorite things to do.