The Ei164RC is a Heat Alarm that runs on 230V AC mains power, and has built in tamper-proof rechargeable Lithium cells that act as a battery backup in the event of mains failure. These rechargeable cells are designed to have a ten-year life and outlast the life of the heat alarm itself, whilst providing up to 6 months of heat alarm operation without mains power.

The Alarm gives a fire warning when the temperature at the unit reaches 58oC. Heat alarms are designed for use in kitchens and garages, where the use of optical or ionisation alarms would lead to unwanted nuisance alarms.