During the winter months we install tube heaters in the engine bay of Naughty-Cal to keep the frost at bay and protect the vulnerable raw water cooling elements of the engines coiling system. The closed circuit is obviously protected by anti freeze but the raw, or river water, coolers are unprotected.
But how do we know that they are working? Well ordinarily without lifting the engine hatch you wouldn't know. So to prevent having to do this a couple of times a weekend, years ago we bought a weather station with a remote sensor which we fitted in the engine bay. This recorded the temperature and humidity in the engine bay and also in the cabin where the main unit lives.
Our current weather station is some 6 years old now and was occasionally losing signal from the remote sensor so we have decided that it is about time we buy another one. So yesterday I ordered a new one from Ebay for the princely sum of £16. It won't be delivered until the middle of next week but we plan to put the engine bay heater in place this weekend anyway as the evenings have started to get a bit on the chilly side.