3 69-1676—1
STEP 1. PREPARE FOR INSTALLATION
Check Table 1, the compatibility chart, to make sure the thermostat is compatible with your system. If your system
is not compatible, call Honeywell Customer Care, toll-free, 1-800-468-1502.
Table 1. Compatibility Chart.
aCompatible with 2-wire Honeywell zone valves. Not compatible with Taco zone valves and 2- or 3-wire White-
Rodgers zone valves (No. 1311 and 1361).
bNot compatible with any 120/240 volt system.

Package Contents

Thermostat Decorator cover plate Screws and wall anchors
Wiring labels Owner’s Guide

Tools for Installation

• Screwdriver • Drill • Hammer
Needle nose pliers Drill bits (3/16 in. drywall,
7/32 in. plaster)
System Type
Compatibility with
CT8775A
Compatibility with
CT8775C
Gas or Oil Warm Air Yes Yes
Electric Warm Air No Yes
Gas or Oil Hot Water YesaYes a
Gas or Oil Steam Yes Yes
Gas or Oil Gravity Yes Yes
Gas Millivolt No No
Electric Air Conditioning No Yes
Baseboard Electric (120/240 line volt)bNo No
Single Stage Heat Pump No Yes
Multistage Heat Pumps/Multistage Equipment No No