When we designed our house we wanted a low energy usage, low maintenance house, and Wendy insisted on a KISS approach to operating it. So we have one simple control for water temperature and air temperature. Water is set at 45C and air at 23C and Wendy is happy that if I'm not around she is able to keep everything going. I'm hoping that we will be able to gradually reduce the air temperature as we get used to living in a PH. We had the thermostat set to 24C in the bungalow because of the cold spots that existed in there but as there are none in the house we should be able to get it down to 21C eventually without Wendy feeling uncomfortable.