background image

69-0959

10

T8501A,B,C,D MICROELECTRONIC THERMOSTATS

TROUBLESHOOTING GUIDE (Continued)

a

Available on select models.

Symptom

Possible Cause

Action

Heating will not
come on.

Thermostat minimum off time is
activated.

Wait up to five minutes for the system to respond.

(Continued)

System selection is not set to
Heat.

Set system selection to Heat.

Cooling will not
come on.

No power to the thermostat.

Check that C terminal is connected to the system
transformer.

Check for 24 Vac between C and R or RC and Y terminals.

If missing 24 Vac:

check if the circuit breaker is tripped—reset the
circuit breaker.

check if the system fuse is blown—replace the fuse.  

check if the system switch at the equipment is in the
Off position—set to the On position.

check wiring between thermostat and HVAC
equipment—replace any broken wires and tighten
any loose connections.

If 24 Vac is present, proceed with troubleshooting.

Thermostat 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 number 02 and reconfigure the fan
operation.

Conventional heating  
equipment turns on the fan
when the furnace has  
warmed up to a setpoint.

Wait a minute after seeing the On indicator and then check the
registers.

Heating equipment is not
operating.

Verify operation of heating equipment in self-test.

Outdoor
temperature  
not displayed

a

Option not activated.

Enter Installer Setup mode number 24 and set to 01.
Thermostat must have OT terminals and a C7089B1000
installed.

Outdoor
temperature  

Outdoor sensor is connected
incorrectly.

Refer to C7089B1000 installation instructions and check wiring
between the thermostat and sensor.

display is incorrect

a

Wrong sensor.

Replace sensor with C7089B1000 sensor.

Содержание t8501A

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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...

Страница 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 ...

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

Страница 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 ...

Отзывы: