Honeywell CT3550 Manual

A SERVICE OF

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7 69-1284—2

Replacing a Thermostat that has Three Wires

If

y

ou have three wires for a heatin

g

onl

y

s

y

stem and can operate the fan usin

g

the fan ON switch this thermostat

works with

y

our s

y

stem. However, some hot water (zoned) heatin

g

s

y

stems also have three wires. Your thermostat will

work onl

y

if

y

ou install an isolatin

g

rela

y

on these s

y

stems. For details, call

y

our local heatin

g

and/or coolin

g

contractor.

STEP 3. MOUNT THERMOSTAT WALLPLATE

❑ Separate the wallplate from the thermostat b

y

placin

g

y

our thumb or fin

g

ers between

the bottom of the wallplate and the thermostat, and pullin

g

the wallplate up and awa

y

from the thermostat. See illustration at ri

g

ht.

❑ Position the wallplate on the wall. Level the wallplate for appearance if desired. Use a

pencil to mark the two mountin

g

holes that best fit the application.

❑ Remove the wallplate from the wall. Drill two 3/16 in. holes in wall (if dr

y

wall) as shown.

For materials such as plaster or wood, drill 7/32 in. holes where marked. Gentl

y

, tap the

(provided) anchors into the drilled holes until the

y

are flush with the wall.

❑ Reposition the wallplate over the holes. Pull the wires throu

g

h the wirin

g

openin

g

.

Loosel

y

insert mountin

g

screws into each of the holes.

❑ Level the wallplate if desired. Thermostat functions

properl

y

when not level.

❑ Ti

g

hten mountin

g

screws.

M16427

WIRES

THROUGH WALL

WALL

MOUNTING

HOLES

M15044

MOUNTING

SCREWS

WALL

ANCHORS (2)