Honeywell PRO TH4110B, Installation Manual, Page: 2 / 16

Product Application
This thermostat provides electronic control of 24 VAC single-stage heating and cool-
ing systems, or 750 mV heating systems.
System Types
• Gas, oil, or electric heat with air
conditioning
• Warm air, hot water, high-efficiency
furnaces, heat pumps, steam, gravity
• Heat only
• Heat only with fan
• Cool only
• 750 mV heating systems
Power Type
• AA alkaline batteries (2)
System Settings
• Heat, Off, Cool
Fan Settings
• Auto, On
Must be installed by a trained, experienced technician
• Read these instructions carefully. Failure to follow these instructions can dam-
age the product or cause a hazardous condition.
• Check the ratings in this booklet to verify that this product is suitable for your
application (see page 12).
• Always test for proper operation after installation (see pages 8-9).
CAUTION: ELECTRICAL HAZARD
Can cause electrical shock or equipment damage. Disconnect power before
beginning installation.
MERCURY NOTICE
If this product is replacing a control that contains mercury in a sealed tube, do not
place the old control in the trash. Contact your local waste management authority for
instructions regarding recycling and proper disposal.
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