I needed to monitor my boilers activity as I thought something may not be quite right about its activity – gas usage is fairly high and our thermostat is fairly low – only 18 degrees C. Our thermostat is programmed to become active twice a day, in the morning, and then in the late afternoon to evening. During this time the thermostat switches a wire to live (230v) to signal heat requested to the boiler, which is an older and not very efficient model. I decided to build a quick and dirty d...
