Temperature zones may be set in either Fahrenheit or Celsius
degrees. The default temperature scale is Fahrenheit.

To change to Celsius:

1. Press SENSOR ON/OFF.

2. Press °F / °C. The Model 400 responds: “Degrees Celsius” indicating Celsius scale has replaced Fahrenheit scale.

3. To return to Fahrenheit scale, repeat the key sequence. The Model 400 responds: “Degrees Fahrenheit” indicating Fahrenheit scale is in effect.

NOTE When switching from Fahrenheit to Celsius, or vice versa, the change applies to all zones configured to read temperature. When switching temperature scales it is important to reset high and low temperature limits on all temperature zones.