White Rodgers T25 Leaflet

The performance specifications are nominal and conform to acceptable industry standards. For applications at conditions beyond these specifications, consult the local Johnson Controls office.
Johnson Controls, Inc. shall not be liable for damages resulting from misapplication or misuse of its products. © 2009 Johnson Controls, Inc.

Knob

SPDT, permits system shutdown 
at the thermostat

Off-Auto

1-3 /4 (1)

2-1/4 (1.3)

1.3

SPDT, used when the same device
controls heating and cooling

Heat-Off-Cool

SPDT, used to control separate
loads on heating and cooling

SPDT, heavy duty, used to control 
separate loads on heating and cooling

3 (1.7)

3 to 4 (1.7 to 2.2)

SPDT

None

1-3/4 (1)

2-1/4 (1.3)

1.0

SPDT, heavy duty

3 (1.7)

3 to 4 (1.7 to 2.2)

Knob

Two SPDT switches
Two-stage heating, cooling or one
stage heating and one stage cooling

None

1-3/4 (1)

2-1/4 (1.3)

1.5

3 (1.7) between stages

Concealed

1. For the thermostat guard, refer to G Series Thermostat and Humidistat Guards Catalog Page, LIT-1922145.
2. Can also be used where one unit provides both heating and cooling by adding a jumper between terminals 2 and 3. (See Typical Wiring Diagram and Electrical 

Ratings for Line Voltage Thermostats Catalog Page, LIT-1922600.)

3. Includes a faceplate for horizontal mounting. The plate is for on-the-job installation over a vertical plate. 

Can field-convert to other configurations.
The T26S-18 is a universal replacement for Honeywell T451A, -B, T651A; White Rodgers 179-1, 180-1, 181-1, 182-101, -102; Robertshaw TA500, TH71, 
-72, -79, -500, TX550.
T26T-3 replaces: Honeywell T4051A, -B, T6051A; White-Rodgers 151-6, 152-9, 159-3, -5.