In Case Of Difficulty - Honeywell RTH221 Operating Manual

Operating Manual

In case of difficulty

Screen is blank.
Temperature settings cannot be
changed.
Cool On or Heat On is flashing. • The compressor protection delay is underway. Wait for the delay
HI appears on the screen.
LO appears on the screen.
E1 appears on the screen.
E2 appears on the screen.
• Ensure two fresh AAA alkaline batteries are correctly installed.
• The System switch is off.
• You are setting the temperature outside its allowable range:
• Heat: 40°F to 90°F (4.5°C to 32°C)
• Cool: 50°F to 99°F (10°C to 37°C)
to end (maximum of 5 minutes).
• The ambient (measured) temperature is above 122°F (50°C).
• The ambient (measured) temperature is below 32°F (0°C).
• The temperature sensor circuit is opened. Replace the thermostat.
• The temperature sensor circuit is shorted. Replace the thermostat.
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