Murder keping the temp up with our current weather mate but i didnt get no probs and mine was dropping down to around the same at lights off .What i done was brought my lights on temp down so that their wasnt a massive drop when the lights went out as imo dropping from 78 to 59 is worst than dropping from 70 to 59 or have your lights come on at the coldest part of the day and off at the warmest . be safe mate and hope you sort it out .the postman.