White Rodgers 750 Thermostat User Manual

Home

href="
CONTENTS  
Preparations.................................................. 1  
Thermostat Details ........................................ 1  
Removing Old Thermostat ............................ 1  
Mounting and Wiring ..................................... 2  
Check Thermostat Operation ........................ 3  
Programming your Thermostat ..................... 4  
Specifications ................................................ 6  
Troubleshooting ............................................ 6  
Installation Instructions for  
Heating & Cooling  
Digital Model 750  
5/2 Day Programmable  
Thermostat  
YOUR THERMOSTAT REPLACES  
PREPARATIONS  
1
Description  
750  
Assemble tools required as shown below.  
Standard Heat & Cooling Systems 4 or 5 wires  
Standard Heat Only Systems  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
Yes  
No  
Millivolt Heat Only Systems Floor or Wall Furnaces  
Standard Central Air Conditioning  
FLAT BLADE SCREWDRIVER  
HAND OR POWER  
DRILL WITH 3/16 INCH  
DRILL BIT, IF NEEDED  
Gas or Oil Heat  
Electric Furnace  
Hydronic (Hot Water) Zone Heat 2 Wires  
Hydronic (Hot Water) Zone Heat 3 Wires  
Heat Pump (No Aux or Emergency Heat)  
Heat Pump (with Aux or Emergency Heat)  
Baseboard Electric Heating or Line Voltage (120 or 240 volt)  
WIRE CUTTER/STRIPPER  
Yes  
No  
Failure to follow and read all instructions carefully  
before installing or operating this control could cause  
personal injury and/or property damage  
No  
THERMOSTAT DETAILS  
REMOVING OLD THERMOSTAT  
2
3
Mounting  
hole  
CAUTION  
!
To prevent electrical shock and/or equipment damage,  
disconnect electrical power to the system at the main  
fuse or circuit breaker until installation is complete.  
-
-
+
+
W903  
Clip to  
Disable  
EMR  
Before removing wires from old thermostat’s switching subbase,  
label each wire with the terminal designation it was removed from.  
W
RH  
B
RC  
Feature  
1. Remove Old Thermostat: A standard heat/cool thermostat  
consists of three basic parts:  
a. The cover, which may be either a snap-on or hinge type.  
b. The base, which is removed by loosening all captive screws.  
G
O
Y
Mounting  
hole  
W903  
W904  
W905  
W905  
Clip for  
Hydronic  
System  
c. The switching subbase, which is removed by unscrewing  
themountingscrewsthatholditonthewalloradaptorplate.  
ELEC GAS  
2. Shut off electricity at the main fuse box until installation is  
complete. Ensure that electrical power is disconnected.  
3. Remove the front cover of the old thermostat. With wires still  
attached,removewallplatefromthewall.Iftheoldthermostat  
has a wall mounting plate, remove the thermostat and the wall  
mounting plate as an assembly.  
W904  
Clip for  
Celsius Display  
Electric/Gas  
Switch  
Figure 1. Thermostat base  
4. Identify each wire attached to the old thermostat.  
5. Disconnectthewiresfromtheoldthermostatoneatatime.DO  
NOT LET WIRES FALL BACK INTO THE WALL.  
6. Install new thermostat using the following procedures.  
WHITE-RODGERS  
EMERSON ELECTRIC CO.  
9797 REAVIS ROAD  
ST. LOUIS, MISSOURI 63123-5398  
PART NO. 37-6319D  
Replaces 37-6319C  
0435  
href="
REMOVING OLD THERMOSTAT  
3
4
CAUTION  
Take care when securing and routing wires so they do  
not short to adjacent terminals or rear of thermostat.  
Personal injury and/or property damage may occur.  
!
CONTINUED FROM FIRST PAGE  
ATTENTION! This product does not contain mercury. How-  
ever, this product may replace a unit which contains mercury.  
Do not open mercury cells. If a cell becomes damaged, do not  
touch any spilled mercury. Wearing non-absorbent gloves, take  
up the spilled mercury and place into a container which can be  
sealed. If a cell becomes damaged, the unit should be discarded.  
TERMINAL CROSS REFERENCE CHART  
New Thermostat  
Other Manufacturers’  
Mercury must not be discarded in household trash. When the unit  
this product is replacing is to be discarded, place in a suitable  
container and return to White-Rodgers at 2895 Harrison Street,  
Batesville, AR, 72501-2117 for proper disposal.  
Terminal Designation  
Terminal Designation  
*
*
RH  
RC  
G
4
R
G
W
Y
RH  
R
M
V
F
R5  
-
R
-
G
G
4
G
W
Y
W
W
Y
H
C
MOUNTING AND WIRING  
Y
Y6  
* These are four-wire, single-transformer systems.  
Factory installed jumper wire between the RH  
and RC terminals must remain in place.  
WARNING  
!
Do not use on circuits exceeding specified voltage.  
Higher voltage will damage control and could cause  
shock or fire hazard.  
Do not short out terminals on gas valve or primary  
control to test. Short or incorrect wiring will damage  
thermostat and could cause personal injury and/or  
property damage.  
Energy Management Recovery (EMR)  
This thermostat is set to operate with EMR. This causes the  
thermostat to start the heating or cooling system early to have  
the room temperature reach the program setpoint at the time  
the period is to start.  
Thermostat installation and all components of the sys-  
tem shall conform to Class II circuits per the NEC code.  
To disable EMR, clip jumper W903 (see Fig. 1).  
Electric Heat or Single-Stage  
Heat Pump Systems  
Attach Thermostat Base to Wall  
1. Remove the packing material from the thermostat. Gently pull  
the cover straight off the base. Forcing or prying on the  
thermostat will cause damage to the unit. If necessary, move  
the electric heat switch (see ELECTRIC HEAT SYSTEMS,  
above).  
This thermostat is configured from the factory to operate a heat/  
cool, fossil fuel (gas, oil, etc.), forced air system. It is configured  
correctly for any system that DOES NOT require the thermostat  
to energize the fan on a call for heat. If your system is an electric  
or heat-pump system that REQUIRES the thermostat to turn on  
the fan on a call for heat, locate the GAS/ELECTRIC switch (see  
fig. 1) and switch it to the ELECTRIC position. This will allow the  
thermostattoenergizethefanimmediatelyonacallforheat.Ifyou  
are unsure if the heating/cooling system requires the thermostat  
to control the fan, contact a qualified heating and air conditioning  
service person.  
2. Connect wires beneath terminal screws on base using appro-  
priate wiring schematic (see figs. 2 through 7).  
3. Placebaseoverholeinwallandmarkmountingholelocations  
on wall using base as a template.  
4. Move base out of the way. Drill mounting holes.  
5. Fasten base loosely to wall, as shown in fig. 1, using two  
mounting screws. Adjust until level, and then tighten screws.  
(Leveling is for appearance only and will not affect thermostat  
operation.) If you are using existing mounting holes, or if holes  
drilled are too large and do not allow you to tighten base  
snugly, use plastic screw anchors to secure subbase.  
Hydronic (Hot Water or Steam)  
Heating Systems  
Thisthermostatissettooperateproperlywithaforced-airheating  
system. If you have a hydronic heating system (a system that  
heats with hot water or steam), you must set the thermostat to  
operate properly with your system.  
6. Push excess wire into wall and plug hole with a fire-resistant  
material (such as fiberglass insulation) to prevent drafts from  
affecting thermostat operation.  
The factory default setting is forced air heat. Clipping jumper  
W905 on the circuit board will produce a longer heating cycle  
which is normally for hot water or steam (hydronic) systems. Both  
settings produce a very accurate temperature control and can be  
set to your personal preference. As received, the thermostat  
cycles the system just under 1˚F. With W905 clipped, the system  
cycles at approximately 1.5˚F.  
Battery Location  
This thermostat requires 2 AAAalkaline batteries to operate.  
If “LO BATTERY” is displayed, the batteries are low and should  
be replaced with fresh AAAEnergizer® alkaline batteries. To  
replacethebatteries, installthebatteriesalongthetopofthebase  
(see fig. 1). The batteries must be installed with the positive(+)  
ends to the right.  
href="
MOUNTING AND WIRING  
CONTINUED FROM SECOND PAGE  
4
JUMPER  
THERMOSTAT  
SYSTEM  
Hot  
WIRE  
Y
B
O
G
W
RC  
RH  
THERMOSTAT  
SYSTEM  
Y
B
O
G
W
RC  
RH  
Cooling  
System Relay System  
Fan  
Heating  
24 VAC  
120 VAC  
Neutral  
Fan  
Relay  
Heating  
System  
Hot  
HEATING  
TRANSFORMER  
24 VAC  
120 VAC  
Neutral  
NOTE  
For 2-wire Heat only,  
attach to RH and W  
Hot  
TRANSFORMER  
24 VAC  
120 VAC  
Neutral  
Figure 2. Typical wiring diagram for  
COOLING TRANSFORMER  
heat only, 3-wire, single transformer systems  
Figure 5. Typical wiring diagram for  
heat/cool, 5-wire, two-transformer systems  
JUMPER  
WIRE  
THERMOSTAT  
Y
B
O
G
W
RC  
RH  
SYSTEM  
JUMPER  
WIRE  
JUMPER  
WIRE  
THERMOSTAT  
SYSTEM  
Cooling  
System Relay  
Fan  
Y
B
O
G
W
RC RH  
Hot  
24 VAC  
120 VAC  
Neutral  
Reversing Compressor Fan  
Valve*  
Contactor Relay  
Hot  
TRANSFORMER  
24 VAC  
120 VAC  
Neutral  
Figure 3. Typical wiring diagram for  
cool only, 3-wire, single transformer systems  
* Reversing valve is energized when the  
system switch is in the COOL position  
TRANSFORMER  
Figure 6. Typical wiring diagram for heat pump  
with reversing valve energized in COOL  
NOTE  
RED jumper wire (provided with thermostat) must be  
connected between thermostat RH and RC terminals  
for proper thermostat operation with this system.  
JUMPER  
WIRE  
JUMPER  
WIRE  
JUMPER  
WIRE  
THERMOSTAT  
SYSTEM  
THERMOSTAT  
SYSTEM  
Y
B
O
G
W
RC RH  
Y
B
O
G
W
RC RH  
Cooling  
System Relay  
Fan  
Heating  
System  
Reversing Compressor Fan  
Valve*  
Contactor Relay  
Hot  
Hot  
24 VAC  
120 VAC  
Neutral  
24 VAC  
120 VAC  
Neutral  
* Reversing valve is energized when the  
system switch is in the HEAT position  
TRANSFORMER  
TRANSFORMER  
Figure 7. Typical wiring diagram for heat pump  
with reversing valve energized in HEAT  
Figure 4. Typical wiring diagram for  
heat/cool, 4-wire, single transformer systems  
CHECK THERMOSTAT OPERATION  
5
This thermostat has a time delay between cooling cycles to allow  
the head pressure in the compressor to stabilize. If the tempera-  
ture is adjusted to call for cool within 5 minutes of the last cycle the  
snowflake icon will blink indicating the thermostat is locked out.  
After 3 to 5 minutes, the compressor will start and the snowflake  
icon will stop flashing. This helps prevent the compressor from  
cycling too quickly and is normal operation for the thermostat.  
NOTE  
To prevent static discharge problems, touch side of ther-  
mostattoreleasestaticbuild-upbeforetouchinganykeys.  
If at any time during testing your system does not operate  
properly, contact a qualified serviceperson.  
Fan Operation  
If your system does not have a G terminal connection, skip to  
Heating System.  
1. Move SYSTEM switch to COOL position.  
2. Press  
to adjust thermostat setting below room tempera-  
ture. The blower should come on immediately on high speed,  
followed by cold air circulation  
1. Turn on power to the system.  
2. Move FAN switch to ON position. The blower should begin to  
3. Press  
to adjust temperature setting above room tem-  
operate.  
perature. The cooling system should stop operating.  
3. Move FAN switch to AUTO position. The blower should stop  
Heating System  
immediately.  
1. Move SYSTEM switch to HEAT position. If the heating system  
has a standing pilot, be sure to light it.  
2. Press  
to adjust thermostat setting above room tempera-  
ture. The heating system should begin to operate.  
CAUTION  
!
3. Press  
to adjust temperature setting below room tem-  
To prevent compressor and/or property damage, if the  
outdoortemperatureisbelow50°F, DONOToperatethe  
cooling system.  
perature. The heating system should stop operating.  
href="
CHECK THERMOSTAT OPERATION  
CONTINUED FROM THIRD PAGE  
5
Before you begin programming your thermostat, you should be  
familiar with its features and with the display and the location and  
operation of the thermostat buttons. Your thermostat consists of  
two parts: the thermostat cover and the base. To remove the  
cover, gently pull it straight out from the base. To replace the  
cover, line up the cover with the base and press gently until the  
cover snaps onto the base.  
The Thermostat Buttons and Switches  
FAN  
SYSTEM  
1
2
3
4
5
6
7
8
(Up arrow) Raises temperature setting.  
(Down arrow) Lowers temperature setting.  
ON AUTO COOL OFF HEAT  
TIME button.  
PRGM (program) button.  
RUN (program) button.  
HOLD button.  
FAN switch (ON, AUTO).  
SYSTEM switch (COOL, OFF, HEAT).  
The Display  
9
Indicates day of the week.  
Figure 8. Thermostat display, buttons, and switches  
is displayed when the SYSTEM switch is in the HEAT  
10  
position.  
is displayed (non-flashing) when the SYSTEM  
is displayed (flashing)  
switch is in the COOL position.  
temperature by pressing  
hold the room temperature at the selected setting until you  
press the RUN button to start program operation again.  
or  
. The thermostat will  
when the compressor is in lockout mode.  
Alternately displays current time and temperature.  
11  
ENERGYMANAGEMENTRECOVERYEnergyManage-  
ment Recovery (EMR) causes the thermostat to start heating  
or cooling early to make the building temperature reach the  
program setpoint at the time you specify. Heating will start 5  
minutes early for every 1° of temperature required to reach  
setpoint. Cooling will start approximately 15 minutes early for  
every 1° because it takes longer to reach temperature.  
Clipping W903 jumper will disable EMR.  
12 LO BATTERYis displayed when the 2 AAAbatteries are  
low and should be replaced. Nothing else will be displayed.  
13 Displayscurrentlyprogrammedsettemperature(thisisblank  
when SYSTEM switch is in the OFF position).  
HOLDis displayed when the thermostat is in the HOLD  
14  
mode.  
Example: You select EMR and have your heating pro-  
grammed to 65° at night and 70° at 7 AM. If the building  
temperature is 65° the difference between 65° and 70° is 5°.  
Allowing 5 minutes per degree the thermostat setpoint will  
change to 70° at 6:35 AM.  
Operating Features  
Now that you are familiar with the thermostat buttons and display,  
read the following information to learn about the many features of  
the thermostat.  
°F/°C CONVERTIBILITY The factory default setting is  
Fahrenheit. Clipping W904 jumper on the circuit board (see  
fig. 1) will alter this feature to Celsius temperature setting.  
SIMULTANEOUSHEATING/COOLINGPROGRAMSTOR-  
AGEWhenprogramming, youcanenterbothyourheating  
and cooling programs at the same time. There is no need to  
reprogram the thermostat at the beginning of each season.  
LOW BATTERY INDICATOR If the 2 AAAalkaline batter-  
ies are low and should be replaced, the display will be blank  
except for LO BATTERY. When the batteries are low,  
pressing any button will cause the display to operate for ten  
seconds. After ten seconds, the display will return to blank  
except for LO BATTERY. After LO BATTERYhas been  
displayedfor4weeks,thethermostatwillraisethetemperature  
10 degrees above your setpoint on COOL mode and will drop  
temperature 10 degrees below your setpoint on HEAT mode.  
You cannot program with low batteries, but you can override  
setpoint temperature.  
TEMPERATUREOVERRIDEPress  
or  
untilthe  
display shows the temperature you want. The thermostat will  
override current programming and keep the room tempera-  
tureattheselectedtemperatureuntilthenextprogramperiod  
begins. Then the thermostat will automatically revert to the  
program.  
HOLD TEMPERATURE The thermostat can hold any  
temperature within its range for an indefinite period, without  
reverting to the programmed temperature. Press HOLD  
button. HOLDwill be displayed. Then choose the desired  
href="
TEMPERATURE DISPLAY ADJUSTMENT Your new  
thermostat has been accurately set in our factory. However,  
if you wish, you may adjust your new thermostat temperature  
display to match your old thermostat. This can be accom-  
plished (within a ±3° range) as follows:  
Entering Your Program  
Follow these steps to enter the heating and cooling programs you  
have selected.  
Set Current Time and Day  
1. Press PRGM and RUN buttons at the same time.  
1. Press TIME button once. The display will show the hour only.  
2. Press  
or  
to adjust the displayed temperature to  
your desired setting.  
3. Press RUN to resume normal program operation.  
PM  
EXAMPLE:  
Display Backlight (Not available on earlier models.) The  
display backlight improves display contrast in low lighting  
conditions. Selecting backlight ON will turn the light on for a  
short period of time after any button is pressed. Selecting  
backlight OFF (default) will keep the light off. Turn the display  
backlight feature ON as follows:  
2. Press and hold either  
or  
until you reach the correct  
hour and AM/PM designation (AM begins at midnight; PM  
begins at noon).  
3. PressTIMEonce.Thedisplaywindowwillshowtheminutesonly.  
EXAMPLE:  
1. Press TIME and RUN buttons at the same time. The  
display will show d-Land OFFalternately.  
2. Press  
or  
to change OFFto ON”  
4. Press and hold either  
minutes.  
or  
until you reach the correct  
5. Press TIME once. The display will show the day of the week.  
6. Press or untilyoureachthecurrentdayoftheweek.  
PROGRAMMINGYOUR THERMOSTAT  
6
This section will help you plan your thermostats program to meet  
your needs. For maximum comfort and efficiency, keep the  
following guidelines in mind when planning your program.  
When heating (cooling) your building, program the tempera-  
tures to be cooler (warmer) when the building is vacant or  
during periods of low activity.  
7. Press RUN once. The display will show the correct time and  
room temperature alternately.  
Enter Heating Program  
1. Move the SYSTEM switch to HEAT.  
2. Press PRGM once. A(indicating weekday program) will ap-  
pearinthedisplay.Alsodisplayedarethecurrentlyprogrammed  
start time for the 1st heating period and the currently pro-  
grammed temperature (flashing).  
During early morning hours, the need for cooling is usually  
minimal.  
Look at the factory preprogrammed times and temperatures shown  
below. If this program will suit your needs, simply press the RUN  
button to begin running the factory preset program.  
If you want to change the preprogrammed times and tempera-  
tures, follow these steps.  
MO TU WE TH FR  
AM  
EXAMPLE:  
This display window shows that for the 1st weekday period,  
the start time is 6:00 AM, and 70° is the programmed tempera-  
ture (this example reflects factory preprogramming).  
Determine the time periods and temperatures for your weekday  
and weekend programs. You must program four periods for both  
the weekday and weekend program. However, you may use the  
same heating and cooling temperatures for consecutive time  
periods. You can choose start times, heating temperatures, and  
cooling temperatures independently for both weekday and week-  
end programs (for example, you may select 5:00 AM and 70° as  
the weekday 1st period heating start time and temperature, and  
also choose 7:00 AM and 76° as the weekday 1st period cooling  
start time and temperature). Use the table at the bottom of the  
page to plan your program time periods and the temperatures you  
want during each period. You may also want to look at the sample  
program table to get an idea of how the thermostat can be  
programmed.  
3. Press  
or  
to change the displayed temperature to  
your selected temperature for the 1st heating program period.  
4. Press TIME once (the programmed time will flash). Press  
or  
until your selected time appears. The time will  
change in 15 minute increments. When your selected time is  
displayed, press TIME again to return to the change tempera-  
ture mode.  
5. Press PRGM once. The currently programmed start time and  
setpoint temperature for the 2nd heating program period will  
appear.  
SAMPLE  
Heating/Cooling Schedule Plan (Factory Program)  
Heating/Cooling Schedule Plan  
WEEKEND (2 DAY)  
WEEKDAY (5 DAY)  
WEEKEND (2 DAY)  
WEEKDAY (5 DAY)  
Start  
Time  
Start  
Time  
Start  
Time  
Start  
Time  
Period  
1ST  
Temperature  
70 F  
Temperature  
70 F  
Period  
Temperature  
Temperature  
6:00 AM  
6:00 AM  
1ST  
2ND  
3RD  
4TH  
1ST  
2ND  
3RD  
4TH  
8:00 AM  
5:00 PM  
10:00 PM  
6:00 AM  
8:00 AM  
5:00 PM  
10:00 PM  
62 F  
70 F  
62 F  
78 F  
85 F  
78 F  
82 F  
8:00 AM  
5:00 PM  
10:00 PM  
6:00 AM  
8:00 AM  
5:00 PM  
10:00 PM  
62 F  
70 F  
62 F  
78 F  
85 F  
78 F  
82 F  
2ND  
3RD  
4TH  
1ST  
2ND  
3RD  
4TH  
href="
PROGRAMMINGYOUR THERMOSTAT  
CONTINUED FROM FIFTH PAGE  
6
6. Repeat steps 4 and 5 to select the start time and heating  
temperature for the 2nd heating program period.  
Check Your Programming  
Follow these steps to check your thermostat programming one  
final time before beginning thermostat operation.  
1. Move SYSTEM switch to HEAT position.  
7. Repeat steps 4 through 6 for the 3rd and 4th heating program  
periods. Weekday heating programs are now complete.  
8. PressPRGMonce.SASU(indicatingweekendprogram)will  
appear in the display, along with the start time for the 1st  
heating period and the currently programmed temperature.  
2. Press PRGM to view the 1st weekday heating period time and  
temperature. Each time you press PRGM, the next heating  
period time and temperature will be displayed in sequence for  
weekday, then weekend program periods (you may change  
any time or temperature during this procedure).  
9. Repeat steps 4 through 8 to complete weekend heating  
programming.  
10.When you have completed entering your heating program,  
press RUN.  
3. Press RUN.  
4. Move SYSTEM switch to COOL position.  
5. Repeat step 2 to check cooling temperatures.  
6. Press RUN to begin program operation.  
Enter Cooling Program  
If the outside temperature is below 50°F, disconnect  
powertothecoolingsystembeforeprogramming. Ener-  
gizing the air conditioner compressor during cold  
weather may cause personal injury or property damage.  
1. Move SYSTEM switch to COOL position.  
YOURTHERMOSTATISNOWCOMPLETELYPROGRAMMED  
AND READY TO AUTOMATICALLY PROVIDE MAXIMUM  
COMFORT AND EFFICIENCY!  
2. Follow the procedure for entering your heating program, using  
your selected cooling times and temperatures.  
SPECIFICATIONS  
ELECTRICAL DATA  
7
THERMAL DATA  
Electrical Rating:  
Setpoint Temperature Range:  
45°F to 90°F (7°C to 32°C)  
Operating Ambient Temperature Range:  
32°F to 105°F  
MV to 30 VAC 50/60 Hz. or D.C.  
0.05 to 1.0 Amps (Load per terminal)  
1.5 Amps Maximum Total Load (All terminals combined)  
Operating Humidity Range:  
0 to 90% RH (non-condensing)  
Shipping Temperature Range:  
-40°F to 150°F  
TROUBLESHOOTING  
8
Reset Operation  
reset and still does not function correctly contact your heating/  
cooling service person or place of purchase.  
If a voltage spike or static discharge blanks out the display or  
causes erratic thermostat operation you can reset the thermostat  
Batteries  
by pressing  
,
and TIME at the same time. This also  
For optimum performance, we recommend replacing batteries  
resets the factory defaults. If the thermostat has power, has been  
®
once a year with fresh AAAEnergizer alkaline batteries.  
Symptom  
Possible Cause  
Corrective Action  
No Heat/No Cool/No Fan  
(common problems)  
1. Blown fuse or tripped circuit breaker.  
2. Furnace power switch to OFF.  
Replace fuse or reset breaker.  
Turn switch to ON.  
3. Furnace blower compartment door or  
panel loose or not properly installed.  
Replace door panel in proper position to engage  
safety interlock or door switch.  
No Heat  
1. Pilot light not lit.  
Re-light pilot.  
2. SYSTEM Switch not set to HEAT.  
Set SYSTEM Switch to HEAT and raise setpoint  
temperature above room temperature.  
3. Loose connection to thermostat or system.  
Verify thermostat and system wires are securely  
attached.  
4. Furnace Lock-Out Condition. Heat may also  
be intermittent.  
Many furnaces have safety devices that shut  
down when a lock-out condition occurs. If the  
heat works intermittently contact the furnace  
manufacturer or local service person for  
assistance.  
href="
TROUBLESHOOTING  
8
Symptom  
Possible Cause  
Corrective Action  
No Heat (continued)  
5. Heating system requires service or  
raise thermostat requires replacement.  
Diagnostic: Set SYSTEM Switch to HEAT and  
the setpoint above room temperature. Within a few  
seconds the thermostat should make a soft click  
sound. This sound usually indicates the thermo-  
stat is operating properly. If the thermostat does  
not click, try the reset operation listed above. If the  
thermostat does not click after being reset contact  
your heating and cooling service person or place  
of purchase for a replacement. If the thermostat  
clicks, contact the furnace manufacturer or a  
service person to verify the heating is operating  
correctly.  
No Cool  
1. SYSTEM Switch not set to COOL.  
Set SYSTEM Switch to COOL and lower setpoint  
temperature below room temperature.  
2. Loose connection to thermostat or system.  
Verify thermostat and system wires are securely  
attached.  
3. Cooling system requires service or  
thermostat requires replacement.  
Same procedure as diagnostic for No Heat  
condition except set the thermostat to COOL and  
lower the setpoint below the room temperature.  
There may be up to a five minute delay before the  
thermostat clicks in Cooling.  
Heat, Cool or Fan Runs Constantly.  
1. Possible short in wiring.  
Check each wire connection to verify they are not  
shorted or touching together. No bare wire should  
stick out from under terminal screws. Try resetting  
the thermostat as described above. If the condition  
persists the manufacturer of your system or  
2. Possible short in thermostat.  
3. Possible short in heat/cool/fan system.  
4. FAN Switch set to Fan ON.  
service person can instruct you on how to test the  
Heat/Cool system for correct operation. If the  
system operates correctly, replace the thermostat.  
Furnace Cycles Too Fast or Too Slow  
(narrow or wide temperature swing)  
1. The location of the thermostat and/or the  
size of the Heating System may be  
influencing the cycle rate.  
Digital thermostats normally provide precise  
temperature control and may cycle faster than  
some older mechanical models. A faster cycle  
rate means the unit turns on and off more  
frequently but runs for a shorter time so there is  
no increase in energy use. If you would like to  
increase the cycle time, clip Jumper W-905 as  
mentioned in the instructions for Hydronic Heating  
Systems. It is not possible to shorten the cycle  
time. If an acceptable cycle rate is not achieved as  
received or by clipping W-905 contact a local  
service person for additional suggestions.  
Cooling Cycles Too Fast or Too Slow  
(narrow or wide temperature swing)  
1. The location of the thermostat and the size  
of the Cooling System can influence the  
cycle rate.  
The cycle rate for cooling is fixed and can not be  
adjusted. Contact a local service person for  
suggestions.  
Thermostat Setting and Thermostat  
Thermometer Disagree  
1. Thermostat thermometer setting requires  
adjustment.  
The thermometer can be adjusted +/- 3 degrees.  
See Temperature Display Adjustment in the  
Operation section.  
Thermostat Does Not Follow Program  
1. AM or PM set incorrectly in program.  
2. AM or PM set incorrectly on the clock.  
3. Voltage spike or static discharge.  
Check current clock and program settings  
including the AM or PM designations for each  
time period. If a voltage spike or a static discharge  
occurs use the Reset Operation listed above.  
Blank Display and/or Keypad  
Not Responding  
1. Voltage spike or static discharge.  
2. Battery change required.  
Replace batteries and check heat/cool system  
for proper operation. If a voltage spike occurs use  
the Reset Operation listed above.  

Aprilaire 8061 Thermostat User Manual

Honeywell T8090A191108A Thermostat User Manual

Honeywell HE150 Thermostat User Manual

Honeywell RTH6450D1009E1 Thermostat User Manual

Honeywell CT87 Thermostat User Manual

Honeywell R7851C Thermostat User Manual

Lux Products PSD111 Thermostat User Manual

Honeywell 7351F Thermostat User Manual

Emerson 850 Thermostat User Manual

Honeywell Q7300L Thermostat User Manual