Terminal Designations
This thermostat is shipped from the factory to operate a conventional heating
and cooling system. This thermostat may also be configured for a heat pump
system. See the “heat pump” configuration step on page 17 of this manual to
configure the thermostat for heat pump applications.
Wiring
Terminal
2 Heat 2 Cool
Conventional
System
2 Heat 1 Cool
Heat Pump
System
4 Heat 2 Cool
Heat Pump
System
RC
RH
C
B
O
G
W/E
Y
Y2
W2
Transformer power
(cooling)
Transformer power
(heating)
Transformer
common
Fan relay
First stage
of heat
First stage
of cool
Second stage
of cool
Second stage
of heat
Transformer power
(cooling)
Transformer power
(heating)
Transformer
common
Fan relay
Emergency Heat
First stage of
heat & cool
N/A
Auxiliary heat
Transformer power
(cooling)
Transformer power
(heating)
Transformer
common
Wiring
Caution:
Electrical Hazard
All components of the control
system and the thermostat
installation must conform to
Class II circuits per the NEC Code.
Warning:
Do not overtighten terminal
block screws, as this can
damage the terminal block.
A damaged terminal block
can keep the thermostat
from fitting on the subbase
correctly or cause system
operation issues.
Installation Tip
Max Torque = 6in-lbs.
Wiring
If you are replacing a thermostat,
make note of the terminal
connections on the thermostat that
is being replaced. In some cases
the wiring connections will not be
color coded. For example, the
green wire may not be connected
to the
G
terminal.
Loosen the terminal block screws.
Insert wires then retighten the
terminal block screws.
Place nonflammable insulation into
the wall opening to prevent drafts.
1.
2.
3.
Wiring Tips
C Terminal
The C (common wire) terminal does
not have to be connected when the
thermostat is powered by batteries.
Wire Specifications
Use shielded or non-shielded 18-22
gauge thermostat wire.
Failure to disconnect the power
before beginning to install this
product can cause electrical shock
or equipment damage.
Note:
In many heat pump systems with
no emergency heat relay, a jumper
can be installed between
E
and
W2
to turn thermostat into a single
stage control for Emergency Heat
Operation.
Thermostat Quick Reference
Displays the current room temperature
Time and day of the week / Sensor / Humidity
Staging Indicators:
+1 will appear in the display when second stage of
heat or cool is on. +2 will appear for the third stage of heat.
Setpoint:
Displays the user selectable setpoint temperature.
Hold:
is displayed when the thermostat program is permanently overridden.
System Operation Indicators:
If these or the Fan indicator are flashing, it means that the system is in a
delay of some type (compressor delay, cooling fan delay, staging delay).
Low Battery Indicator:
Replace batteries when this indicator is shown.
Program Menu Options:
Show different options during programming.
Program Time Periods - Residential:
Uses 4 time periods - WAKE, RETURN,
LEAVE & SLEEP.
Commercial:
Uses 2 or 4 time periods that appear in the text
field - Occupied & Unoccupied.
Getting to know your thermostat
Thermostat Quick Reference
5
6
9
10
Battery Installation
Battery installation is recommended even if the thermostat is
hardwired (C terminal connected). When the thermostat is hardwired
and batteries are installed, the thermostat will activate a compressor
delay of 5 minutes when it detects a power outage from the hardwired
power supply.
Important:
High quality alkaline batteries are recommended.
Rechargeable batteries or low quality batteries
do not guarantee a 1-year life span.
Insert 2 AA Alkaline batteries
(included). High quality alkaline
batteries are recommended.
Simple operating instructions
are found on the back of the
battery door.
To release battery cover press finger bevel
on the left side and lift the cover to access
batteries.
S1/S2
Remote Sensor
Remote Sensor
Outdoor temperature sensor, Indoor temperature sensors, and Slab sensor
wiring diagrams are located in R250S and R251S manuals.
Note:
H
Humidify
Humidify
D
Dehumidify
Dehumidify
Energy Efficient Globe:
Indicates you are making energy efficient choices.
Keypad Lockout:
Lock the thermostat
Fan relay
Second stage of
auxiliary heat
Remote Sensor
Humidify
Dehumidify
First stage of
auxiliary heat
First stage of
heat & cool
Second stage
of heat & cool
5 Heat 3 Cool
Heat Pump
System
Transformer power
(cooling)
Transformer power
(heating)
Transformer
common
Fan relay
Second stage of
auxiliary heat
(5th stage of heat)
Remote Sensor
Humidify
Dehumidify
First stage of
auxiliary heat
(4th stage of heat)
First stage of
heat & cool
Second stage
of heat & cool
Reversing valve /
3rd stage of heat
& cool
Reversing valve /
3rd stage of heat
& cool
Reversing valve
/ configurable
terminal
Reversing valve
/ configurable
terminal
Reversing valve
/ configurable
terminal
Reversing valve
/ configurable
terminal
Reversing valve
/ configurable
terminal
Reversing valve
/ configurable
terminal
