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69-0959

5

T8501A,B,C,D MICROELECTRONIC THERMOSTATS

Mode Number
(Press 

  i   

key

Factory-Setting

Other Choices  

(Press 

 or  

 key to change)

Select

to change)

Display

Description

Display

Description

Not used

01

Fan operation

a

02

00

Conventional applica-
tions where equipment
controls fan operation in
heat mode

01

Heat pump and electric heat
applications where thermostat
controls fan operation in heat
mode

Not used

03

Heating cycle rate 04

06

6 cph used for
conventional systems

01, 03,  
or 09

01—1 cph used for radiant floor

heat, gravity systems

03—3 cph used for hot water

systems or high efficiency
furnaces

09—9 cph used for electric heat

systems

Not used

05 thru 11

Changeover
(T8501D only)

12  

01

Automatic changeover

00

Manual changeover

The Installer Setup is used to customize the thermostat to
specific systems. Some of the options include temperature
display, changeover, minimum equipment on time and
minimum off time. Installer modes are listed in numerical
order in Table 2. The table includes all the configuration
options and the factory-settings available for the T8501.

IMPORTANT

The Installer Setup must be set correctly for the
HVAC equipment, thermostat and subbase to
operate properly.

A combination of key presses are required to use the
Installer Setup feature.

To enter the Installer Setup mode, press and hold the
Information

   i   

key with the increase 

 and decrease

 keys until the first mode number is displayed. All

display segments appear for approximately three
seconds before the mode number is displayed. See
Figs. 11 and 12.

To advance to the next Installer Setup mode, press
the Information

   i   

key.

To change a setting, use the increase 

 or de-

crease 

 key.

To exit the Installer Setup mode, press and hold the
Information

   i   

key until the display returns to normal

(approximately three seconds). The display scrolls the
Mode Numbers backwards to get to the normal
display. The Installer Setup mode is automatically
exited if no key presses are made for five minutes.

NOTE: Only configurable Mode Numbers are shown.

Fig. 11. Display of all the segments of the LCD.

Fig. 12. Display of Installer Setup mode and setting.

CAUTION

Heat pump and electric heat systems must be
configured to 01 in Installer Setup mode 02 to
prevent equipment damage caused by the system
running without the fan.

Table  2. Thermostat Installer Setup Options.

a

Available on select models.

(Continued)

M10105

MODE NUMBER DISPLAY 
(COLUMN 2 OF TABLE 2)

FACTORY SETTING OR
OTHER CHOICE DISPLAY
(COLUMN 3 OR 5 OF TABLE 2)

Em HeatOffCool Auto Only

Heat Cool

OnAuto

System

Fan

Room

Outdoor

Em Ht Temporary Setting

Wait

%Humid

Aux Ht

Remote

Repl

Batt

M4844

Summary of Contents for t8501A

Page 1: ...g installation use these instructions to check out the product operation T8501 System Changeover System Selection Fan Selection Comments A Heat only None None None B Heat only None Heat Off On Auto Select models have only a system switch or fan switch and some models have both C Heat Cool Manual Heat Off Cool On Auto System and fan selections are done by switches D Heat Cool Automatic Heat Off Coo...

Page 2: ...he holes 쐂 Tighten mounting screws WIRING All wiring must comply with local electrical codes and ordinances Refer to Fig 3 through 5 for typical hookups A letter code is located near each terminal for identifica tion CAUTION Disconnect power before wiring to prevent electrical shock or equipment damage 쐃 Loosen the terminal screws on the wallplate and connect the system wires See Fig 6 IMPORTANT U...

Page 3: ...O G Y W OUTDOOR TEMPERATURE SENSOR COOL CHANGEOVER VALVE OR DAMPER HEAT CHANGEOVER VALVE OR DAMPER THERMOSTAT 1 2 2 M4826 FOR WRAPAROUND INSERTION STRIP 7 16 IN 11 MM FOR STRAIGHT INSERTION STRIP 5 16 IN 8 MM L1 HOT L2 POWER SUPPLY PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED AVAILABLE ON SELECT MODELS JUMPER Rh TO Rc IN A SINGLE TRANSFORMER SYSTEM 1 HEATING RELAY OR VALVE COIL M48...

Page 4: ...with your fingertip or similar blunt tool Sharp instruments like a pen or pencil point can damage the keyboard Temperature Settings The default setpoint for heat is 70 F 21 C and for cool is 78 F 25 5 C Press the increase or decrease key to change the present setting To change between heat and cool press the Information i key until the setting to be changed appears INSTALLER SETUP NOTE For most ap...

Page 5: ...on of key presses are required to use the Installer Setup feature To enter the Installer Setup mode press and hold the Information i key with the increase and decrease keys until the first mode number is displayed All display segments appear for approximately three seconds before the mode number is displayed See Figs 11 and 12 To advance to the next Installer Setup mode press the Information i key...

Page 6: ...perate Not used 25 thru 32 Minimum off time for the compressor 33 05 5 minute minimum off time for the compressor 00 01 02 03 or 04 Minimum number of minutes 0 thru 5 the compressor will be off between calls for the compressor Heating setpoint range stopa 34 90 Heating setpoint can be set no higher than 90 F 40 thru 90 Number can be set anywhere between 40 and 90 in 1 F increments Cooling setpoint...

Page 7: ...two zeros appear Continued Em HeatOffCool Auto Only Heat Cool OnAuto System Fan Room Outdoor Em Ht Temporary Setting Wait Humid Aux Ht Remote Repl Batt M4844 M6792 TEST MODE NUMBER Test Number Self Test Description 10 19 Heating equipment can be turned on and off 30 39 Cooling equipment can be turned on and off 40 49 Fan equipment T8501D only can be turned on and off 60 69 System key or system swi...

Page 8: ...ss Test Mode Number Description Key or Switch Operation Self Test a IMPORTANT Test Mode Numbers will only be displayed when the system is configured for the selected function EXAMPLE Numbers 60 61 and 62 are the only numbers that will be displayed when a system is configured for heat only SYSTEM KEY OR SWITCH SELF TEST When system switch is used move switch to see Test Mode Numbers i 60 Change fro...

Page 9: ...d tighten any loose connections If 24 Vac is present proceed with troubleshooting Thermostat microprocessor is locked up Remove the thermostat from the wallplate for 2 minutes After 2 minutes replace the thermostat on the wallplate Temperature display is incorrect Room temperature display has been reconfigured Enter Installer Setup mode number 37 and reconfigure the display Thermostat is configure...

Page 10: ...ostat minimum off time is activated Wait up to five minutes for the system to respond Enter Installer Setup mode number 33 Reconfigure minimum off time if required System selection is not set to Cool Set system selection to Cool System On indicator is lit but no heat is being delivered Fan operation set for 00 conventional heat when it should be set for 01 electric heat Enter Installer Setup mode ...

Page 11: ...69 0959 11 T8501A B C D MICROELECTRONIC THERMOSTATS ...

Page 12: ...uilding Control Honeywell Limited Honeywell Limitée 155 Gordon Baker Road North York Ontario M2H 2C9 69 0959 J H 10 96 Printed in Taiwan R O C Home and Building Control Honeywell Inc Honeywell Plaza P O Box 524 Minneapolis MN 55408 0524 www honeywell com yourhome ...

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