Bah. On any given day, there’s only about a 50% chance the central heating in our house works.

As the central heating season faded out in April and May this year, we had a heating zone control valve stick. Since the valve didn’t send a “complete” signal to the controller, this pretty much overode all of the controls. The thermostat and the timer just didn’t work. The heating was either on or off. So for the last few weeks we just used the isolating switch on the boiler when we wanted a bit of heat boost. And we got used to the idea that the heating wasn’t automatic.

I let it fester a bit over the summer unfixed. We turned the gas boiler off entirely and relied on the immersion heater and the solar panel for hot water over the summer. I eventually tidied my office enough for an engineer to get to the airing cupboard, and phoned up the insurance company.

Phoning the insurance company is always a pain, but the engineers they send usually know what they’re doing. They located the central heating pump – it’s unhelpfully under the floor – replaced it, replaced the zone control valve, fine tuned the boiler, and it all seemed to be working just fine when they left.

But now, a few weeks later, and there’s another fault. The boiler is definitely working, and it seems to be heating the hot water just fine. The HZCV doesn’t seem to be stuck. The pump is running, and you can hear water swilling around the radiators. But barely any of them are getting warm. Gah!