Honeywell CHRONOTHERM IV DELUXE T8624D, Product Data, Page: 19 / 20

T8624D CHRONOTHERM ® IV DELUXE PROGRAMMABLE THERMOSTAT
68-0166—1 19
CROSS REFERENCE
Refer to Table 13 for thermostat cross referencing information.
Table 13. Thermostat Cross Reference Information.
Model Number Description
TRADELINE 
Replacement Remarks
T8624C Two-stage heat and two-stage cool conventional thermostat; powered direct from 24 Vac
transformer; manual changeover; system switch—HEAT-OFF-COOL-AUTO;
fan switch—ON-AUTO; O and B terminals
T8624C1008 Trane; Premier White  color; part no.
TAYSTAT302A.
T8624D2004 Wiring differences (old=new): B=C;
jumper R to Rc; taupe color.
T8624D Two-stage heat and two-stage cool conventional thermostat; powered direct from 24 Vac
transformer; automatic changeover; system switch—HEAT-OFF-COOL-AUTO;
fan switch—ON-AUTO; O and B terminals
T8624D1006 TRADELINE  thermostat; Honeywell logo. T8624D2004 Configure changeover to auto in
Installer Setup 12.
T8624D1014 Carrier Weathermaker. T8624D2004 Configure changeover to auto in
Installer Setup 12.
T8624D1022 Carrier Zone Perfect. T8624D2004 Configure changeover to auto in
Installer Setup 12.
T8624D1030 TRADELINE

thermostat; Honeywell logo;
Premier White

color.
T8624D2004 Configure changeover to auto in
Installer Setup 12; taupe color.
T8624D1055 York logo. T8624D2004 Configure changeover to auto in
Installer Setup 12.
T8624D1063 Trane; Premier White

color. T8624D2004 Wiring differences (old=new): B=C;
jumper R to Rc; taupe color.
Symptom Possible Cause Action
Cooling will not
come on. No power to the thermostat. • Check for 24 Vac between R and C.
—
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 power switch on the HVAC 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 number 33. Reconfigure minimum off time
(if required).
System selection is not set to
Cool. Set system selection to Cool.
Cool setpoint is above room
temperature. Check cooling setpoint. Set cooling setpoint to desired
temperature.
Outdoor temperature
not displayed
a
Option not activated. Enter Installer Setup number 24 and set to 1. Thermostat must
have OT terminals and a C7089B1000 installed.
Outdoor temperature
display is incorrect
a
Outdoor sensor is connected
incorrectly. Refer to C7089B1000 installation instructions and check wiring
between the thermostat and sensor.
Wrong sensor. Replace sensor with C7089B1000 sensor.
a
Available on select models.
Table 12. Troubleshooting Information (continued).