How can I tell if the heating cable is working from the app? There's a lot of heat loss going from over 30' during the day to under 15' at night. Heating set to come on at 18'. Thanks

Hi Elaine - the app won't tell you if the cable is working - the best way is to feel it by hand. The cable won't always be able to maintain your target greenhouse temperature, there is only so much power one can put in, vs the heat loss through the greenhouse structure / outside ambient temperature / wind conditions etc. It's intended to be a gentle warming to keep the greenhouse as close to your target temperature as possible.