The HD135 heat alarm is for use as a warning device in residential applications. Each alarm has a solid state piezo signal to warn and alert the household to the presence of threatening heat.
The HD135 alarm is designed to detect heat that results from an actual fire. Heat alarms are intended for use as supplements to smoke alarms. This unit cannot detect smoke or other toxic gases, therefore, do not rely solely on this heat alarm to provide a warning of fire.
In the event AC Power fails, a 9VDC battery will provide proper alarm operation for a minimum of a 24-hour period.