Electronic Devices Jure Brence, Ziga Gosar, Vid Serazin, Jernej Zupancic, Matjaz Gams 8 2 2019 https://doi.org/10.6025/ed/2019/8/2/31-36 http://www.dline.info/ed/fulltext/v8n2/edv8n2_1.pdf In this paper we present our work on the optimisation of water heater scheduling. The goal is to develop intelligent strategies for controlling the electric heater and heat pump in commercial combined water heaters. Strategies try to find the best compromise between comfort and price, based only on information about the temperature of water in the reservoir. A simulation and testing environment has been implemented to compare the performance of existing and new strategies.