Hi all. I have recently moved into a new home with a hot water cylinder and my gas usage since I have lived here has been rather high - around 660kWh per month despite no central heating being on. The previous owner kept the hot water on constantly all day and I blindly followed suit until the most recent month when I programmed my thermostat for the hot water to come on only twice a day, but my usage remained the same. I have since discovered that my boiler is firing up every time I turn a hot tap on, which I imagine is what is causing the high usage. I thought it might be a communication problem with the thermostat but the central heating appears to be unaffected. Can anyone help? Does this sound like something a heating engineer could easily fix? Thank you.