White Rodgers 850 Installation Instructions Manual

Installation Instructions for
Heating & Cooling
Digital Model 850
5/1/1 Day Programmable
Thermostat
YOUR THERMOSTAT REPLACES
Description
Standard Heat & Cooling Systems - 4 or 5 wires
Standard Heat Only Systems
Millivolt Heat Only Systems - Floor or Wall Furnaces
Standard Central Air Conditioning
Gas or Oil Heat
Electric Furnace
Hydronic (Hot Water) Zone Heat - 2 Wires
Hydronic (Hot Water) Zone Heat - 3 Wires
Heat Pump (No Aux or Emergency Heat)
Heat Pump (with Aux or Emergency Heat)
Baseboard Electric Heating or Line Voltage (120 or 240 volt)
2

THERMOSTAT DETAILS

Mounting
Electric/Gas
holes
switch
Figure 1. Thermostat base
1
850
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
No
No
3
Screw anchors
Mounting
holes
White-Rodgers is a division
of Emerson Electric Co.
www.white-rodgers.com
CONTENTS
Preparations .................................................. 1
Thermostat Details ........................................ 1
Removing Old Thermostat ............................ 1
Mounting and Wiring ..................................... 2
Check Thermostat Operation ........................ 4
Specifications ................................................ 7
Troubleshooting ............................................ 7

PREPARATIONS

Assemble tools required as shown below.
FLAT BLADE SCREWDRIVER
HAND OR POWER
DRILL WITH 3/16 INCH
DRILL BIT, IF NEEDED
SPIRIT LEVEL OR PLUMB BOB AND LINE (OPTIONAL)
Failure to follow and read all instructions carefully
before installing or operating this control could cause
personal injury and/or property damage.

REMOVING OLD THERMOSTAT

CAUTION
!
To prevent electrical shock and/or equipment damage,
disconnect electrical power to the system at the main
fuse or circuit breaker until installation is complete.
Before removing wires from old thermostat's switching subbase,
label each wire with the terminal designation it was removed from.
1. Remove Old Thermostat: A standard heat/cool thermostat
consists of three basic parts:
a. The cover, which may be either a snap-on or hinge type.
b. The base, which is removed by loosening all captive screws.
c. The switching subbase, which is removed by unscrewing
the mounting screws that hold it on the wall or adaptor plate.
2. Shut off electricity at the main fuse box until installation is
complete. Ensure that electrical power is disconnected.
3. Remove the front cover of the old thermostat. With wires still
attached, remove wall plate from the wall. If the old thermostat
has a wall mounting plate, remove the thermostat and the wall
mounting plate as an assembly.
4. Identify each wire attached to the old thermostat using the
labels enclosed with the new thermostat.
5. Disconnect the wires from the old thermostat one at a time. DO
NOT LET WIRES FALL BACK INTO THE WALL.
6. Install new thermostat using the following procedures.
WIRE CUTTER/STRIPPER
PART NO. 37-6295B
Replaces 37-6295A
0514