Hot plumber John turns up. With slightly less hot colleague, but who cares?
They look at my boiler, tut and grin.
"Seen many Bond movies, James?" they ask. "Well, you know what happens when the needle goes into the red? The piranhas escape and your island base explodes. Thing is mate, that needle there on your boiler has gone waaaay past the red."
I look ashen. A new boiler is three grand without even blinking.
They grin. "We could tell you you need a new boiler, or something. But it just means that the chumps who installed it left a tap on. It'll take a second to turn that off... And then your boiler won't blow up next week."
Great thing about Hot Plumber is that he's good with the bad news.