Honeywell T8775A

1 69-1677ES—1
INSTALLATION INSTRUCTIONS
® U.S. Registered Trademark • Patents Pending
© 2004 Honeywell International Inc.
All Rights Reserved
69-1677ES—1
T8775A,C
The Digital Round
™
Non-Programmable Thermostats
The T8775A,C Thermostats provide single-stage
temperature control for 24V systems. The
T8775A,C models include a thermostat, wallplate
(for wiring and mounting thermostat), mounting
screws, wall anchors, and a 4074 FAB resistor.
MERCURY NOTICE
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 an old
control containing mercury in a sealed
tube.
INSTALLATION
When Installing this Product…
1. Read these instructions carefully. Failure to
follow them could damage the product or
cause a hazardous condition.
2. Check the ratings given in the instructions
and on the product to make sure the product
is suitable for your application.
3. Installer must be a trained, experienced ser-
vice technician.
4. After installation is complete, check out prod-
uct operation as provided in these instruc-
tions.
CAUTION
Electrical Shock or Equipment Damage
Hazard.
Can shock individuals or short
equipment circuitry.
Disconnect power supply before
installation.
Location
Install the thermostat about 5 ft (1.5m) above the
floor in an area with good air circulation at average
temperature. Do not install the thermostat where it
can be affected by:
— drafts or dead spots behind doors and in
corners.
— hot or cold air from ducts.
— radiant heat from the sun or appliances.
— concealed pipes and chimneys.
— unheated (uncooled) areas such as an outside
wall behind the thermostat.
Mounting Wallplate to Wall
Mount the T8775A,C wallplate, with the screws
provided. See Fig. 1.
Fig. 1. Mounting wallplate to wall.
M19499
WALL ANCHORS (2)
WIRING HOLE
WALL PLATE
1 INCH SCREW (2)
1 WHEN USING WALL ANCHORS, DRILL 3/16 IN. HOLES
FOR DRYWALL, 7/32 IN. HOLES FOR PLASTER.
1

Honeywell T8775A Specifications

General

Voltage	24V AC
Color	White
Stages	1 Heat/1 Cool
Power Method	Hardwired
Temperature Range	40°F to 90°F
Compatibility	Single-stage heating and cooling systems
Mounting	Wall-mounted
Display	LCD

Summary

INSTALLATION

Location

Optimal placement for thermostat installation to ensure accurate temperature readings.

Mounting Wallplate to Wall

Instructions for securely attaching the thermostat wallplate to the wall.

Installation Precautions

Key steps and warnings to follow before and during product installation.

Wiring

Wiring Guidelines

Important instructions on wire gauge, electrical codes, and power disconnection for thermostat wiring.

CUSTOMIZE THERMOSTAT

Setting Fuel Switch

How to set the fuel switch on the T8775C for different heating systems.

Setting FahrenheitCelsius Display

Instructions for using DIP switch 3 to select temperature display units.

DIP Switch Settings

Details on configuring heat cycle rate and temperature units using DIP switches.

OPERATION

System and Fan Switch Settings

Manual control of heating, cooling, and fan operation using thermostat switches.

Checkout Procedure

Steps to verify proper operation of heating, cooling, and fan functions after installation.