Timeguard ntt01 24 hour compact immersion heater timeswitch timeguard ntt01 p the timeguard ntt01 is a 24 hour compact immersion heater segment timeswitch the timeswitch is a easy to use and fits on to a single gang wall box it can control outputs of up to 16a which makes it suitable for domestic immersion heaters p timeguard ntt01 24 hour compact immersion heater timeswitch