Trane thermostat troubleshooting

Trane thermostats produce comfort temperature in the premises. And Trane thermostat troubleshooting system provides comfortable diagnostics and repairs. It is provided below in form of a table understandable for any user.

SymptomPossible CauseAction
Display will not come on.Thermostat is not being powered.Check if the thermostat is mounted and latched on the wallplate-mount and latch the thermostat on the wallplate.
Check if the circuit breaker is tripped-reset the circuit breaker.
Check if the fuse is blown-replace the fuse. Check if the system switch is in the Off position-set to Heat or Cool.
Temperature settings will not change (Example: cannot set the heating higher or the cooling lower).The upper or lower temperature limits were reached.Check that the temperature setpoints are within range:
Heating: 50° to 99° F (10° to 37° C) Cooling: 50° to 99° F (10° to 37° C).
Heating will not come on.No power to the thermostat.
System selection is not set to Heat. Heating setpoint is below room temperature.
Check that the setpoint is above room temperature-reset temperature or wait for room temperature to fall.
Check if the circuit breaker is tripped-reset the circuit breaker.
Check if the fuse is blown-replace the fuse. Check if the system switch at the equipment is in the Off position-set to Heat position. Wait five minutes for the system to respond.
Cooling will not come on.No power to the thermostat.
System selection is not set to Cool. Cooling setpoint is above room temperature.

Check that the setpoint is below room temperature-reset temperature or wait for room temperature to rise.
Check if the circuit breaker is tripped-reset the circuit breaker.
Check if the fuse is blown-replace the fuse. Check if the system switch at the equipment is in the Off position-set to Cool position. Wait five minutes for the system to respond.
System on indicator (5) and is lit, but no warm or cool air is coming from the registers.Heating/cooling equipment turns on the fan when the equipment has reached the setpoint.Wait a minute after seeing the flame or snowflake and then check the registers.
System on indicator (5) or^c is flashingMinimum off timer is in effect.Wait five minutes until the minimum off timer is complete.

Trane 190  series thermostat troubleshooting

Problems symptomsProblem causeAction recommended
A) The compressor does not start up
Compressor terminals are live but motor does not startMotor burned out.Replace compressor
Contactor motor not operational.Coil burned out or broken contacts.Repair or replace.
No current ahead of motor contactor.a) Power cut.Check fuses and connection.
b) Main power supply switched off.See why system tripped.
If system is operational, switch on main power supply.
Current ahead of fuse, but not on contactor side.Fuse blown.Check motor insulation. Replace fuse.
Low voltage reading on voltmeter.Voltage too low.Contact power Supply Utility.
Starter coil not excited.Regulation circuit open.Locate regulation device which has tripped out and see why. See instructions concerning this device.
Replace compressor.
Compressor does not run. Compressor sticking Compressor motor "groans". (damaged or sticking components). High pressure switch tripped to contacts open Discharge pressure too high on high pressure. Discharge pressure too high.See instructions for "discharge pressure high".
B) Compressor stops
High pressure switch tripped.
Over current thermal relay tripped.Discharge pressure too high.See instructions for "discharge pressure high".
a) Voltage too low.a) Contact Power Supply Utility.
b) Cooling demand too high, or condensing temperature too high.b) See instruction "discharge pressure too high".
Motor temperature thermostat tripped. Anti-freeze security tripped.Not enough cooling fluid.Repair leak. Add refrigerant.
C) Compressor stops just after its start
Suction pressure too low. Filter drier iced up.Filter drier clogged.Replace filter drier.
D) The compressor keeps running without stopping
Temperature too high in areas requiring air- conditioning.Excess load on cooling system.Check thermal insulation and air-tightness of areas requiring air-conditioning.
E) Loss of oil in compressor
Oil level too low in indicator.Not enough oil.Contact Trane office before to order oil
Gradual fall in oil level. Suction line too cold. Compressor noisyFilter drier clogged.Replace filter drier.
Liquid flows back to compressor.Adjust superheat and check bulb fixing of the expansion valve.
F) Compressor noisy
Compressor knocks.Components broken in compressor.Change compressor.
Suction line abnormally cold.a) Uneven liquid flow.a) Check superheat setting and fixing of expansion valve bulb.
b) Expansion valve locked in open position.b) Repair or replace.
G) Insufficient cooling capacity
Thermostatic expansion valve "whistles".Not enough refrigerant.Check refrigerant circuit tightness and add refrigerant.
Excess pressure drops through filter drier.Drier filter clogged.Replace.
Excessive superheat.Superheat not properly adjusted.Check adjustment of superheat and adjust thermostatic expansion valve.
H) Discharge pressure too high
Condenser abnormally hot.Presence of uncondensable liquids in system, or excess refrigerant.Purge uncondensable fluids and drain off excess refrigerant.
Condenser air output too hot.Reduced air flow. Air intake temperature higher than specified for unit.Clean battery. Check operation of motor fans.
1) Suction pressure too high
Compressor operates continuously.Excess cooling demand on evaporator.Check system.
Suction duct abnormally cold. Refrigerant flows back to compressor.a) Expansion valve too far open.a) Check for superheat and check that expansion valve bulb is secure.
b) Expansion valve locked in open position.b) Replace.
J) Suction pressure too low
Excessive pressure drop through filter drier. Refrigerant does not flow through thermostatic expansion valveDrier filter clogged.Replace the deshydrator. Replace the bulb.
Expansion valve bulb has lost its refrigerant.
Loss of power.Expansion valve obstructed.Replace.
Superheat too low.Excessive pressure drops through evaporator.Check adjustment of superheat and adjust thermostatic expansion valve.

Trane SENS-IN-1D18-HD60D29-4 thermostat troubleshooting

ProblemSolution
Display does not come on.Check the 24 VAC power supply at terminals 11 and 14 at the Zone Sensor.
Verify that the terminal block is properly positioned on its pins.
No communications to the UCP.Check for 22 to 42 VDC between terminals 11 and 12 at the Zone Sensor.
Check wiring if no voltage is present.
Dispalyed Zone Temperature reads Sh and the COOL FAIL icon is continuiously illuminated.1. Verify that Option 11 in the Options Menu is set correctly. If correct, check the wiring from the remote sensor at terminals S1 and S2 for a shorted
2. If Option 11 in the Options Menu is set to 0, then the local thermistor is selected and the on-board thermistor is shorted and the ZSM must be replaced.
Dispalyed Zone Temperature reads oP and the COOL FAIL icon is continuiously illuminated.1. Verify that Option 11 in the Options Menu is set correctly. If correct, check the wiring from the remote sensor at terminals S1 and S2 for a open circuit
2. If Option 11 in the Options Menu is set to 0, then the local thermistor is selected and the on-board thermistor is open and rhe ZSM must be replaced.
Zone Temperature is not displayed.Verify that number 1 has been selected for option 13 in the Options Menu.
ZSM keypad does not respond to selectionVerify that the Keypad is not in the Lockout Mode. Press and hold the TIME ("+") and Key for 4 seconds to unlock the keypad.
The Clock requires reprogramming after short power interruptions.Replace Battery.
FAN Mode is set in the ON position but the Fan is not running.Check option 6 in the Options Menu. Refer to the Options Menu section for option description.
System is operating before the programmed start time.Check option 7 in the Options Menu. Computed recovery option overrides the last part of an unoccupied period to obtain the occupied setting in time.
Buzzer indicates System Failure or Service is required.Press the ERASE Key to reset the filter lapse timer. Buzzer will be reset until noon of the next day if a System Failure has not been corrected.

Trane TAYSTAT 575 thermostat troubleshooting

SymptomPossible CauseAction
Display does not come on.Thermostat is not being powered.• Check that B terminal is connected to the system transformer.
• Check for 24 Vac between B and R 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 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 microprocessor is locked up.Remove the thermostat from wallplate for 2 minutes. After 2 minutes, replace the thermostat on the wallplate.
Temperature display is incorrect.Room temperature display was reconfigured.Enter Installer Setup Number 37 and reconfigure the display.
Thermostat is configured for ?F or ?C display.Enter Installer Setup Number 14 and reconfigure the display.
Bad thermostat location.Relocate the thermostat.
Temperature settings will not change. (Example: Cannot set the heating higher or the cooling lower.)The upper or lower temperature limits were reached.Check the temperature setpoints:
• Heating limits are 55 to 85°F (13 to 29°C)
• Cooling limits are 65 to 99°F (18 to 37°C).
The setpoint temperature range stops were configured.Check Installer Setup mode numbers 34 and 35 and reconfigure the setpoint stops.
Heating does not come on.No power to the thermostat.• Check that B terminal is connected to the system transformer.
• Check for 24 Vac between B and R 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.
System selection is not set to Heat.Set system selection to Heat.
Heating setpoint is below room temperature.Check heating setpoint. Set heating setpoint to desired temperature.
Cooling does not come on.No power to the thermostat.Check that B terminal is connected to the system transformer.
Check for 24 Vac between B and R 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.Heating equipment is not operating.Verify operation of heating equipment in system test.
Outdoor temperature not displayed.Option not activated.Enter Installer Setup mode number 24 and set to 01. Thermostat must have OT terminals and a TAYSENS100A installed.
Outdoor temperature display is incorrect.Outdoor sensor is connected incorrectly.Refer to TAYSENS100A installation instructions and check wiring between the thermostat and sensor.
Incorrect sensor.Replace sensor with TAYSENS100A Sensor.