Freeze protection
WARNING: Do not use this thermostat for freeze protection.
In cold climates that require the heating system to be used for building freeze protection, a mechanical backup
freeze protection device must be installed on the heating system. This can be a simple mechanical heating
thermostat or a preset thermoswitch installed in the heated area (Figure 15).
Figure 15. Freeze protection
Mechanical thermostat
or thermoswitch
40 to 45°
R
W
Heating system
Red wire
24 VAC R
Heat W
White wire
Thermostat
connections
Wire across heater R/W terminals
21