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.