The PC8900 Control Panel provides 24 Vac energy saving
control for a heating and cooling system, while providing
reliable, precise temperature control, ventilation control,
humidity control, programmable fan control and air filter/
cleaner status information.
The PC8900 must be used with a W8900 Remote Module.
The PC8900 includes a SYSTEM light, which is lit when
the heating or cooling system is running, and a CHECK
light, which lights as a prompt to check messages on the
These models will replace most heating/cooling system
thermostats. Check Table 1 to make sure the thermostat is
compatible with the intended system.
Table 1. Compatibility Chart.
Electric Air Conditioning
(120/240 Line Volt)
Heat Pumps/Multistage Equipment
a Use R8222N Relay if installing as part of millivolt
system (see W8900 Remote Module Instructions form
b Use R8222D Relay if installing as part of a 120/240 Vac
baseboard electric system (see W8900 Remote Module
Instructions, form 69-0894).
U.S. Registered Trademark
Copyright © 1995 Honeywell Inc. •
See Note a
See Note b
• All Rights Reserved
Temperature Setting Range:
45 F to 88 F (7 C to 31 C).
Humidity Setting Range:
10% to 80%.
Operating Relative Humidity:
5% to 90%, noncondensing.
Dimensions in in. (mm):
6-3/8 (163) width x 4 (102) height x 1-5/8 (41) depth.
205224A Wall Cover Plate to cover marks left on the
wall by the old thermostat.
C7189A Wall Mount Indoor Air Temperature Sensor.
C7089A Outdoor Sensor.
If this control is replacing a control that contains
mercury in a sealed tube, do not place your old
control in the trash.
Contact your local waste management authority for
instructions regarding recycling and the proper
disposal of any control containing mercury in a
If you have any questions, call Honeywell Inc. at
1-800-468-1502, Monday through Friday, 7 AM to
5:30 PM, Central time.