In this demonstration, we present a scalable low-cost solution to provide personalized home heating advice to households. Our solution uses a specially designed USB temperature logger, placed on top of the thermostat, to infer the operation of the heating system indirectly. Using additional external temperature data, available through the internet, it builds a simple thermal model of the home, which is then used to calculate the impact, in terms of percentage reduction in heating costs, of various interventions (such as reducing the thermostat set-point temperature); providing specific actionable advice to the household.