Honeywell RTHL2510C Owner's Manual page 7

Alternate wiring (for heat pumps with auxiliary or backup heat only)
If labels do not match letters on the thermostat, check the chart below and
connect to terminal as shown here (see notes, below).
6
L
F
Leave metal jumper in place, connecting
If your old thermostat had both
qualified contractor for help.
If your old thermostat had separate
electrical tape and do not connect.
If your old thermostat had
qualified contractor for help.
Do not use C or X wire. Do not use B wire if you already have O wire.
5
Wrap bare end of wire with electrical tape.
Do not use L wire. Wrap bare end of wire with electrical tape.
6
If your old thermostat had E and Aux wires (or alternate wires), connect both
wires to Aux terminal.
7 Install Batteries
Install two AAA alkaline batteries.
7 3
5
O
E C B
X H
X
X2 B
B O
and
V
,
Y1 W1
RTHXXXX
Back of thermostat
firealarmresources.com
4
7
G
Y AUX
F W
Y1
W1
M
W2
G Y
& terminals.
R Rc
wires, stop now and contact a
VR
and wires, wrap the B wire in
O B
and wires, stop now and contact a
W2
M32707
7
1
2
R
RC
V
VR
R Rc
2
M32728