Honeywell MagicStat CT2400 User manual

PROGRAMMABLE
THERMOSTAT
BY HONEYWELL
PROGRAMMING AND INSTALLATION
INSTRUCTIONS
Weekday/Weekend (5-day/2-day)
Programmable Heat and/or Cool
Low Voltage (20 to 30 Vat)
Thermostat and Mounting Plate
Model CT2400
Limited One-Year Warranty
Honeywell warrants this prcduct, excluding battery, to be free from defects in the workmanship or materials, under normal use and sewice,
for a pericxl of one (1) year from the date of purchase by tha consumer. If, at any lime during the warranty period, the product is defective or
malfunctions, Honeywell shall repair or replace it (at Honeywel~s option) within a reasonable period of time.
[t the product is defective,
(i)
retUrn it, with a bill of sale or,other dated prcof of purchase, to the retailer from which you purchased it, or
(ii) package it carefully, af0n9 wdh Proof of purchase (including date of purchaae) and a short description of the
ma ffuncf ion, and mail it, postage prepaid, to the following address
Honaywall Inc. in Canada: Honeywell Limited/Honeywell Limit6e
Return Goods Department Product Services ON 15-FFE
1050
13erkafdre Lane 74o Ellesmere Road
Plymouth, MN 55441-4437 Scarborough, Ontario Ml P 2V9
This warranty does not cover removal or reinstallation coats. This warranty shall not apply if
It is shown by Honeywell that the defect or
malfunction was caused by damage which occurred while the product was in the possession of a consumer.
Honeywell’s sole responsibility shall be to repair or replace the product within the terms stated above. HONEYWELL SHALL NOT BE LIABLE
FOR ANY LOSS OR DAMAGE OF ANY KIND, INCLUDING ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES RESULTING, DIRECTLY
OR INDIRECTLY, FROM ANY BREACH OF ANY WARRANTY, EXPRESS OR IMPLIED, OR ANY OTHER FAILURE OF THIS PRODUCT.
Some states do not allow the exclusion or limitation of incidental or consequential damages, so this limitation may not apply to you.
THIS WARRANTY IS THE ONLY EXPRESS WARRANTY HONEYWELL MAKES ON THIS PRODUCT. THE DURATION OF ANY IMPLIED
wARRANTIES, INCLUDING THE WARRANTIES OF MERCHANTABILIV AND FITNESS FOR A PARTICULAR PURPOSE, IS HEREBY
LIMITED TO THE ONE YEAR DURATION OF THIS WARRANTY. Some states do not allow Ilmitafions on how long an implied warranty lasts,
so the above limitation may not apply to you.
This warranty givas you specific legal rights, and You may have other
r!ghts which vary from state to state.
If you have any questions concerning this warranty, please write our Customer Assistance Center, Honeywell Inc., P.O. Box 524, Minneapolis,
MN 55440-0524 or call 1-800-468-1502, Monday-Friday, 7:00 a.m. to 5:30 p.m., Central time. In Canada, write Retail Products ON1 5-02H,
Honeywell LimitecUHoneywell Limitee, 740 Ellesmere Road, Scarborough, Ontario Ml P 2V9.
35
TYPICAL ENERGY SAVINGS FOR REPRESENTATIVE CITIES IN THE U.S. AND CANADA
❑ SaviW for Gnc3-A.Oay ❑ SawrQSfciTv4c=3A-CUIy’
l&F [5*C] d— l&F [5-C] decrease.
2
3
so%
~za%
H
fi
Q
“~~ mlwF [50CI dncrease+~F [*C] deciease
Thermostat patents pending.
grfes WP+vxlmateiy 55 pemml ol these savings.) ~z,,~h
Printed in U.S.A. G.S. 7-93 @Honeywell Inc. 1993

Welcome to the world of comfort and
energy savings with your new Honeywell
MagicStat@ programmable thermostat.
Your new thermostat will automatically
control the temperature in your home,
keeping you comfortable while saving energy
when programmed according to the instruc-
tions in this manual.
Direct any questions concerning the
application of this thermostat to Honeywell
Customer Assistance at 1-800-468-1502,
Monday-Friday
7:00 a.m.-53O p.m., Central
time.
@ RECYCLING THERMOSTAT
If this thermostat is replacing a thermostat
that contains mercury in a sealed tube (see
illustration below), do
not place your old
thermostat in the trash. Contact your
Jocal waste
management authority for instructions regarding
the recycling and proper disposal of your old
thermostat.
If you have questions, call Honeywell Inc.
at 1-800-468-1502.
Typical
location of a
MERCURY
SWITCH
mercury
switch in a
thermostat.
w
—.
o
0
M3701
Table Of Contents
STEP 1 Prepare For Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...2
STEP 2 Remove Old Thermostat
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
4
STEP 3 Install The Batteries
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6
STEP 4 Program The Thermostat
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
STEP 5 Adjust Fan Operation Switch, As Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
STEP 6 Adjust System On-Time, As Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
STEP 7 Mount Thermostat Mounting Plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
STEP 8 Wire Thermostat Terminals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..2O
STEP 9 Mount The Thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...24
STEP 10 Check Thermostat Operation After Programming And installing . . . . . . . . . . . . . . . . . . . . . . ...25
STEP 11 Set The Fan And System Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...27
Troubleshooting Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...29
Limited One-Year Warranty
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
35
1
—
❑ Acquire tools and items below as needed. Also purchase two AA alkaline batteries; we
recommend Energizer batteries.
T
~ “(~,
CROSS-RECESSED
SCREWDRIVER iiAND OR POWER .
DRILL WITH 3/16 INCH
DRILL BIT, IF NEEDED, TO
DRILL HOLES IN WALL
~ ~AsKING TAPE ,F
WIRE CUTTEWSTRIPPER OR SHARP
KNIFE, IF NEEDED, TO STRIP WIRES NEEDED, TO
Ll&EL WIRES
AS DISCONNECTED FROM
OLD THERMOSTAT
UIall
ulEa-’-U
LEVEL, IF NEEDED, TO LEVEL
THERMOSTAT FOR APPEARANCE
M378B
3

~ Prepare For Installation
❑ Check Table 1 to make sure this thermostat is compatible with your system. If it is not, return
to retailer. For more information, call Honeywell Customer Assistance, toll-free 1-800-468-1502.
TABLE 1 -COMPATIBILITY CHART.
System Type
Compatible With CT2400
Gas-Standin~ Pilot
Yes
Gas-Electro~c Ignition
Gas-Fired Boilers
EA A
Gas—Millivolt
Oil-Fired Boilers
Y:AA
OWired Furnace
Yes
Electric Furnace Yes
Electric Air Conditioning Yes
Baseboard Electric (120/240 Line Volt)
No
Heat PumpdMultistage Equipment
No
.,-. -- ——-., I-,- . . . ..L ---- .fin/n”n .._i. -:.-..:.
lNoI compaurm WIIrI arly I al~+u VUIL cxrum.
~Compatible with 2-wire Honeywell zone valves. Isolating relay required for3-wire thermo-
stats for zone valves. Not compatible with 2-wire White-Rodgers no. 1361 valves.
~Compatible with hot water baseboard systems. Will not work efficiently on steam or
gravity systems.
7
_ Remove Old Thermostat
[1 Test to make certain that your heating
and cooling systems are working properly. If
either does not work, contact your local
heating/air conditioning dealer. To avoid
compressor damage, do not operate the
cooling system when outdoor temperature is
below 50° F[10° C].
❑ TURN OFF POWER to system at the
furnace, or at the fuse/circuit breaker panel.
U Carefully unpack your new thermostat and
mounting plate; save the package of screws,
instructions and receipt.
URemove cover from old thermostat. If it
does not snap off when pulled firmly from the
bottom, check for a screw used to lock on the
cover.
Replacing a Clock Thermostat that has C
or Cl Clock Terminals?
If you are replacing a Honeywell
Chronotherm@ Thermostat, you may find one
or two wires that go to the C or Cl clock
terminals on the Chronotherm Thermostat
wiring
wallplate. Do not allow them to touch,
or you may damage your transformer.
Disconnect the wires and wrap them sepa-
rately, using electrical tape. Do not wrap them
together. Place the wires where they will not
interfere with the operation of the new
thermostat. Record the colors and terminal
designation labels of the remaining wires.
Six or more wires?
If there are six or more wires (excluding
clock wires attached to terminals), you
most likely have a variation of a heat pump
❑ Loosen screws holding thermostat to
subbase, wallplate or wall, and lift away.
U Disconnect wires from old thermostat or
subbase. As you disconnect each wire, use
masking tape to label it with the old terminal
designation. If there are only two wires, they
do not need to be labeled. If there is an extra
wire that is not connected to your old thermo-
stat, you will
ako not be connecting it to your
new thermostat. Keep the wires from falling
back into the wall by wrapping them around a
pencil as shown.
4
——. .
—
or multistage system. The thermostat is
not compatible with such systems so return
the product to the place of purchase. If you
would like information about which program-
mable thermostats will work with your system,
call Honeywell Customer Assistance at
1-800-468-1502.
Three thermostat wires?
If you have three wires for heating only and
can operate the fan using the fan ON switch,
this thermostat will work with your system.
However, some hot water (zoned) heating
systems have three thermostat wires. The
thermostat will not work without installing an
isolating relay on these systems. For details,
call Honeywell Customer Assistance at 1-800-
468-1502.
5

_ Install The Batteries
IMPORTANT:Batteries must be installed for
programming and operation of the thermo-
stat and heating/cooling system.
❑ Purchase two AA alkaline batteries; non-
alkaline batteries will not last as long, and may
leak, causing damage to thermostat or wall
surface. We recommend Energizer batteries.
•l Make sure the thermostat is set in the OFF
position.
El Use a coin to remove battery door.
❑ Install the fresh batteries as shown,
making sure positive and negative terminals
are oriented correctly.
O Replace battery door.
—
flashing. “bAt Lo” will stay on without flashing,
indicating the thermostat and heating/cooling
system have stopped working and the
batteries are almost completely dead.
After the batteries are completely dead, the
“bAt Lo” indicator will disappear, leaving a
completely blank display.
Press down on left ends of batteries to
remove. If you insert the new batteries within
INSTALL TWO AA ALKALINE
/BATTEFIIESASStiOIAIN
a
: E=l
M171
A
\
M1779B
As the batteries are running low, a “bAt Lo”
indicator will flash for one to two months
before batteries run out completely. Replace
the batteries as soon as possible after the
indicator starts flashing. If you do not replace
the batteries sometime during the flashing
“bAt Lo,” the indicator will eventually stop
6
20 to 30 seconds of removing the old ones,
you will not have to reprogram the thermostat.
However, if the display is blank, the batteries
are dead or incorrectly installed, and you will
have to reprogram. See pages 12 and 13 to
reprogram.
IMPORTANT:Although the thermostat has a
low battery indicator, replace the batteries
once a year to prevent the thermostat and
heatinrjcooling system from shutting down
due to lack of battery power.
As a precaution, when leaving home for
longer than a month, change batteries before
you leave to prevent the system from shutting
down due to lack of battery power.
7
- Program The Thermostat
After the batteries are installed, the thermostat
can be easily programmed in your hand
before it is installed on the wall.
If you would prefer to program the thermostat
after it is installed on the wall, skip to page
8,
and return later to this programming section.
The following personal programming chart
(pages 10 to 11 ) may be helpful for planning
your program schedule of time and tempera-
ture settings for various times of the day.
Four time periods are available during
weekdays — “WAKE,” “LEAVE,” “
RE -
TURN,” and “SLEEP.” These periods can
be seen individually on the display as you
press the SET SCHEDULE key.
n
‘WAKE” is the time period you want the
house at a comfortable temperature when
you get up and while you get ready for work
or school. (This will be a higher temperature
during heating season, or a lower tempera-
ture during cooling season.)
“LEAVE” is the time period you can set for
an energy-saving temperature while you are
away at work or school. (This will be a lower
temperature during heating season, or a
higher temperature during cooling season.)
“RETURN” is the time period you want the
house at a comfortable temperature for
activities before bedtime. (Again, higher
heat or lower cool.)
“SLEEP” is the time period you can set for
an energy-saving temperature while you are

sleeping. (Again, lower heat or higher cool.
For more comfortable sleeping, some
people choose not to raise the cool tem-
perature during the night.)
You will set one schedule for weekdays and
another for weekends, because your require-
ments will probably be different for each.
During weekends, only the “WAKE and
“SLEEP time periods are available.
Fill in the times and temperatures you desire
for weekdays and weekends. If you decide not
to program the thermostat, it will automatically
control heating at 68° F [20° C], and cooling at
78° F [26° C], 24 hours a day. Also, you do not
need to enter a time and temperature program
for all periods if your schedule does not
9
require it. For example, a house that is occu-
pied during weekdays would only require
programs for “WAKE and “SLEEP.”
If no program is entered for the weekends, the
thermostat will operate on the weekday
“SLEEP program all weekend.
When pressing the keys, use the ball of your
finger or a soft pencil eraser. Use of sharp
fingernails or pencil points can damage the
keypad.
If you make an error at any time during
programming, just press the RUN PROGRAM
key, and continue again at the step where you
left off.
Personal Programming Chart
HEATING PROGRAM
A
Weekdays
Start Time Heating Temperature
WAKE
LEAVE
RETURN
SLEEP
A
Weekends i
WAKE
SLEEP
~ If you decide not to enter weekend programs, SLEEP from the weekday program
will copy to the weekend schedule.
~ The temperatures cannot be set any higher than 88° F [31° C] or any lower than
45° F [7: C].
10
.—
COOLING PROGRAM
Weekdays
Start Time
.-
—
Cooling Temperature~
WAKE
LEAVE
RETURN
SLEEP
Weekends
~
WAKE
SLEEP
~ If you decide not to enter weekend programs, SLEEP from the weekday program will copy to
the weekend schedule.
~ The temperatures cannot be set any higher than 88° F [31
0
C] or any lower than 45° F [7° C].
NOTE: If you decide not to program the thermostat, it will automatically control heating at
68° F [20° C], and cooling at 78° F [26° C], 24 hours a day.
11

COOLING PROGRAM
Weekdays
Start Time
Cooling Ternperature~
WAKE
LEAVE
RETURN
SLEEP
Weekends~
WAKE
SLEEP
~ If you decide not to enter weekend programs, SLEEP from the weekday program will copy to
the weekend schedule.
~ The temperatures cannot be set any higher than 88° F [31
0
C] or any lower than 45° F [7° C]
NOTE: If you decide not to program the thermostat, it will automatically control heating at
68° F [20° C], and cooling at 78° F [26° C], 24 hours a day.
11
——-
—
.—
This guide can be used for programming your new thermostat.
NOTE: Batteries are required for operation and programming. When inserting batteries, set
system switch to OFF. Remove battery door (on thermostat left side) using a coin at the
bottom. Follow instructions on pages 6 and 7.
Set Current Time/Day Time
o
0
Ahead
To set time, press and release ~kwma~ once,
n
until current time shows; to set day,
Back
Time
~
pressandreleasewagain, V
n
until current day shows; then press p~lm .
Back
Heating Program
c1
With system switch at HEAT, press and release ~~uk once. “WAKE,” Mon-Fri and “SET”
appear on display.
12
Time Temp
c1
Ahead
0
Warmer
Use
to program “WAKE time and
n
o
to program “WAKE” temperature for
Back Cooler
Mon-Fri. Repeat sequence for “LEAVE,” “RETURN,” “SLEEP.”
Time
c1
n
Ahead
Press ~C~~Ub until “WAKE,” “SA SU” and “SET” appear on display. Use
o
to program
Temp
Back
—
u
Warmer
“WAKE” time and ,—,
to program “WAKE temperature for Sat-Sun. Repeat sequence
for “SLEEP.”
u
Cooler
Cooling Program
With system switch at COOL, follow the same instructions as for Heating Program.
L-1
After programming, adjust fan and system switches as desired. Press and release pr&m to
start the program.
13

—-.
Aquick guide for operating or making changes follows:
NOTE: System switch must be set to Heat or Cool to perform the following:
Temp
—
u
Warmer
Temporarily Change Temperature for Current Period Only—
n
. Temporary indicator will
Cmlar
o
show on display; it will cancel itself at next scheduled change. To cancel sooner, press P~&
Temp
n
u
Warmaf
Hold a Temperature Indefinitely— ~~~P , 0
0
; press pJ& to cancel.
Coobr
14
---
.—
.
n
Check Current Temperature Setting- p;~~m .
(If using Temporarily Change or Hold,
pressing this will cancel your change.)
D
Check Programs— ~~Uk
o
Run
repeatedly to see each time and temperature; then Program .
Time
(
1
c1
Cancel a Program- ~~~Ub until program to cancel shows; then
H
together.
o
Beck
Permanently Change a Program—Repeat steps under Heating Program or Cooling Program
(pages 12 and 13) as applicable.
u
Return to normal program or start program — p;~~m .
~m
: Customer Assistance
_ Adjust Fan Operation Switch, As Required
D The thermostat fan operation switch, labeled electric heat system, set the switch to “E. The
FUEL SWITCH (see illustration on page 17) is “E setting will allow the fan to turn on
immedi-
factory-set in the “F position. This is the correct
ately with the heating or cooling in a system
setting for most systems. If your system is an
where the “G” terminal is connected.
_ Adjust System On-Time, As Required
El The system on-time is facto-~-set for a warm
air, gas or oil heating system. If you are installing
it on another type of system, the system on-time
must be adjusted accordingly by setting screws A
and B on the back of the thermostat. Use the
heating system table shown in the illustration,
(page 17) as a guide. The system on-time should
be optimized according to the type of system to
minimize room temperature swings. Setting the
screw “out one turn” means turning the screw
approximately 360° counterclockwise, or about
one complete turn.
In the unlikely event that you want longer furnace
on-time, readjust screws A and/or B as follows:
First, turn both screws
in completely, then adjust
for system type:
● Warm Air Furnace-Set at the Hot Water
setting, (A - out one turn, B - in).
● Electric Furnace-Leave at the Warm Air
Furnace setting (A - in, B - in).
16

NOTE: This thermostat does not have a setting for steam/gravity air. Cycles would not be long
enough for accurate temperature control.
IMPORTANT: When using a high
efficiency furnace such as a
90 percent or greater Average
Fuel Utilization Efficiency
(AFUE) unit, adjust screw A
OUT ONE TURN and screw
B IN.
THERMOSTAT BACK
.---———
1
Trcl--- .-:-:----------------–– ~-------,
-- ..: ,:. .
1
1
1
1
1
1
1
1
““’::’’mml
t
E
.,W Y G,,’ ;
[G- I
FUEL SWITCH
1
-A
;5, ;&:%_& ;
r-
F~IE “ :--- - ~ :
1
Q’
IR 19),
Rc :
~ ilil
:_
--____ --_____________ :___y:::’’l~lfi
----
-J---- –-- J__;lJ- __;
17
‘ ~ Mount Thermostat Mounting Plate
~ Position mounting plate on wall. Use a level
to make sure mounting plate is level. Use a
~/ ;&ORS
pencil to mark the two mounting holes.
(2)
‘b
18
— —.
— —.
•l Remove mounting plate from wall, and drill
LEVEL
3/1 6 inch holes in wall (if drywall) as marked.
(
HI
la
El
For firmer material such as plaster or wood,
) II
drill 7/32 inch holes. Gently tap anchors
(provided) into drilled holes until flush with the
wall.
❑ Reposition mounting plate over holes,
pulling wires through wiring opening. Loosely
insert two mounting screws into holes.
❑ Level for appearance only; thermostat will
‘,[ ,1=
‘~:
function properly even when not level. Tighten
mounting screws.
M1714A
19

_ Mount The Thermostat
A. ENGAGE TABS AT TOP OF
;;~;f;;N. ~
C. SWING COVER OPEN
THERMOSTAT AND MOUNTING PLATE.
I I
I i/
B. PRESS LOWER EDGE
OF CASE TO LATCH.
T
. >-/ ,., ~
-—
J,(4
A
NOTE: To remove thermostat from wall, first pull out at
bottom of thermostat, removing top last. *4
—. —— —
—
_ Mount The Thermostat
A. ENGAGE TABS AT TOP OF
THERMOSTAT AND MOUNTING PLATE.
B. PRESS LOWER EDGE
OF CASE TO
blTCH.
+
-.
. >-, ,., =
/ -–
J,(4
c.
1
NOTE: To remove thermostat from wall, first pull out at
bottom of thermostat, removing top last. *4
mm
Check Thermostat Operation After
Programming And Installing
HEATING
Do not check heating system
operation by jumpering thermostat
terminals at the primary control such
as the gas valve, zone valve,or oil
burner control. This will damage the
thermostat. Instead, jumper R and W
wires at the thermostat.
Temp
c1
Warmer
Temp
o
Cooler
Move the system switch to HEAT and
the fan switch to AUTO.
Press key until the setting is about
10° F [6° C] above room tempera-
ture. Heating should start and the fan
should run after a short delay
(immediately if fan operation switch is
set in E position).
Press key until setting is about 10° F
[6° C] below room temperature. The
heating equipment should shut off.
25

—
COOLING
To avoid possible compressor
damage, do not operate the
cooling system when outside
temperature is below 50° F
[1 O“ C]. See compressor manu-
facturer instructions for further
information.
NOTE: When cooling setting is
changed, thermostat may delay
up to five minutes before
turning on the air conditioner.
This delay protects the com-
pressor.
Temp
n
Coolar
Temp
n
Warmer
Move the system switch to COOL
and the fan switch to AUTO.
Press key until setting is about 10°
F [6° C] below room temperature.
The cooling equipment and fan
should start.
Press key until the setting is about
10° F [6° C] above room tempera-
ture. The cooling equipment and
fan should stop.
Move the system switch to OFF
with the fan switch still at AUTO.
. .
The system and fan should be off.
26
_ Set The Fan And System Switches ,tio on
First set the fan switch.
FAN AUTO: Normal setting for most
■
r
homes. A sinale-sDeed fan will turn on ~
automatically-with’air conditioner or
furnace. A two-speed fan will usually
run on high with air conditioner and on
low with furnace.
Exception: When Fan Operation
Switch on back of thermostat is set to
“E” position (see page 16), fan will
operate with furnace only.
FAN ON: The fan runs continuously. Auto On
Use for improved air circulation during ~
special occasions or for more efficient
electronic air cleaning. (In a heat-only
system, fan will run continuously only
when fan relay is connected to the
thermostat.)
27
Then set the system switch. COOL: The thermostat controls your
Cgol OJ Hgat
air conditioning system.
OFF: Both the heating and air
conditioning systems are off.
HEAT: The thermostat controls your
C:ol 0/ H~at
heating system.
28

Troubleshooting Guide
IF...
Display will not come on.
Temperature display will not go lower
than 45° F
r“ C] or higher than 88° F
[31
0
C] during programming.
Temperature change occurs at the
wrong times.
Heating will not come on.
THEN...
Set the system switch to OFF. Remove batteries.
Insert batteries backward for
at least five seconds to
reset thermostat. Replace batteries correctly. Display
should come on.
Make sure batteries are fresh and installed correctly.
Gently clean battery contacts using a soft pencil
eraser. Do not use anything abrasive on clips.
You have reached the temperature setting limit.
The setting range is 45° F to 88°F [7°Cto310 C].
Check the program times for the period in
question. Be sure that AM and PM indications
are correct. Make sure the current day and time are
correct. Reprogram if necessary.
Check that switch on thermostat is set to HEAT.
29
Heating will not come on (continued). 9
Cooling will not come on.
The house is too warm or too cool.
SYSTEM ON indicator is lit, but no
heat is coming from the registers.
:
■
■
I
I
(
(
Check the system fuse or circuit breaker and replace
or reset if necessary.
Check for correct wiring and good connections.
Jumper wires R and W. If heat does not come on,
contact your heating dealer.
If display is blank or says “bAt Lo,” install fresh
batteries.
If temperature setting is higher than current tempera-
ture, and SYSTEM ON indicator is lit, contact
Honeywell Customer Assistance at 1-800-468-1502.
Check that switch on thermostat is set to COOL.
Check the system fuse or circuit breaker and replace
or reset if necessary.
Check for correct wiring and good connections.
Jumper wires Rc and Y. If cooling does not come on,
contact your cooling dealer.
If display is blank or says “bAt Lo,” install fresh
batteries.
The thermostat has a built-in time delay on cooling.
Allow five to ten minutes after changing the setting
before the air conditioner starts.
30
Make sure outdoor disconnect is engaged (on).
If temperature setting is lower than current tempera-
ture, and SYSTEM ON indicator is lit, move system
switch from COOL to OFF for ten minutes. After ten
minutes, return switch to COOL position. If air
conditioner comes on, compressor may have reached
its high limit temperature protection and shut down. If
air conditioner does not come on after the ten minutes
and the SYSTEM ON indicator is lit, contact Honey-
well Consumer Assistance at 1-800-468-1502.
If 2- or 4-wire installation, verify that R-Rc jumper is
installed.
Press RUN PROGRAM key to check the current
temperature setting.
f desired, change the temperature setting. See
)age 14.
Wow time for the furnace to heat up and the fan to
:ome on before checking for heat at the register.
Check to make sure system on-time is set
:orrectly according to pages 16 and 17.)
31

—
The furnace cycles too frequently,
■ Readjust system on-time according to instructions on
or the system cycle length
pages 16 and 17.
is too short or too long.
The thermostat current
■ Check that the wiring hole in the wall behind the
setting does not mstch the
wallplate has been plugged with insulation to
display temperature to within t 10.
prevent drafts that might adversely affect
thermostat operation.
■ Be aware that it is normal for the current setting
and display temperature to differ on occasion.
■ During recovery from setback or setup, setting and
display temperatures may differ for up to 30 minutes
after the recovery period.
Incorrect room temperature
showing on thermostat display.
■ Make sure hole behind thermostat is plugged with
insulation to help prevent drafts from adversely
affecting thermostat operation.
■ The thermostat is factory-calibrated, and cannot be
adjusted.
32
Toll-free Customer Assistance
For all questions concerning this thermostat, please read and follow the instructions. If
additional assistance is needed, call Honeywell Customer Assistance toll-free at 1-800-468-
1502, Monday-Friday, 7:00 a.m. -5:30 p.m. Central time.
Before you call, please have the following information available: thermostat model number
and date code, kind of heating/cooling system (i.e., hot water, warm air, oil, gas, etc.), and
number of wires connected to the thermostat.
NOTICE
This equipment is a Class B digital apparatus, which complies with Canadian Radio Interference
Regulations, CRC c. 1374.
33