Honeywell RTHL3550 Installation Guide

SETUP

WIRING

ASSIST

ANCE

TR

OUBLESHOO

TING

Leave metal jumper in place, connecting 

R & Rc 

terminals.
If your old thermostat had both 

V and VR wires, stop 

now and contact a qualified contractor for help.

If your old thermostat had separate 

O and B 

wires, wrap the B wire in electrical tape and do 

not connect.
If your old thermostat had 

Y1, W1 and W2 wires, 

stop now and contact a qualified contractor for 

help.

If there were seperate wires on E and Aux, place 

both wires in the Aux/E terminal.

5

Alternate wiring (for heat pumps only)
If labels do not match letters on the thermostat, check the 

chart below and connect to terminal as shown here (see 

notes, below).

5

4

2

MSCR31275A