Sunvic SunStat Programmable Room Thermostat is a hard wired, battery powered easy to programme and simple to use programmable room thermostat. The 4 daily, independent time and temperature pairs together with TPI controls electronics enables the user to experience a comfortable environment and maximise energy savings. This product is an ideal replacement for the TLX 6501 which is no longer manufactured. Batteries are provided with the unit. The addition of the user activated Delayed Start mode allows the householder to save energy, on warmer days, by delaying switching ON the central heating, for up to one hour, when the actual room temperature is close to the desired room temperature. Features automatic summer time adjust reduces installer call-outs, TPI control electronics saves up to 10% of energy costs, screen lock facility protects against unauthorised changes, frost protection facility protects building and volt free switching ideal for combination boilers.