I have three ‘onewire’ temperature sensors running up from the hot water cylinder and central heating pump to a Raspberry Pi in the loft. These record the water temperature going round the central heating, as well as that going into the hot water cylinder and the temperature of the pipe back to the boiler. The Pi records these every minute.

Nothing whizzy in any of that, it’s all standard stuff. Only I discovered that the temperature readings make a lot more sense if the sensors are actually on the pipes and not sitting in a pile of fluff on the floor! Ah…