Honeywell CT53 User Manual

M23793 

•  2-wire heat-only system: Connect one 

wire to R terminal, one wire to W terminal.

M23791

[1] If wires will be connected to both R and Rc

terminals, remove the metal jumper.

[2] Do not connect both O and B if you have a 

heat pump. Connect only the O wire. Wrap B 

wire with electrical tape and do not use.

[3] Do not use C, X or B. Wrap bare end of wire

with electrical tape.

M23792 

1.  Drill holes at pencil-marked

locations (3/16” holes for  
drywall, 7/32” holes for 
plaster).

2.  Use hammer to tap anchors 

into holes until flush with wall.

3.  Pull wires through thermostat

base and insert screws. 
Check level if desired, then 
tighten screws.

1.  Match each labeled wire with same 

letter on terminal.

2.  Use a screwdriver to loosen screw 

terminals, insert bare wires beneath 

screws, then tighten screws.

3.  Push any excess wire back into the

wall opening.

If labels do not match letters on 

thermostat, see table below.

R • RH • 4 • V 

Terminal “R”

[1]

Rc 

Terminal “Rc”  [1]

O 

Terminal “O”  [2]

B 

Terminal “B”  [2]

G • F 

Terminal “G”

W • W1 • H 

Terminal “W”

Y • Y1 • M 

Terminal “Y”

C • X • B 

Do not use

[3]