Trane Error Codes & Diagnostics
Complete diagnostic directory for official Trane fault codes. Verify root causes, safe troubleshooting steps, and replacement part numbers before calling a technician.
Trane XV20i alerts 184.07 and 184.08 in cold weather: why a working heat pump stays locked out
Both entries describe the state the outdoor control has entered, not a component it has condemned. Trane publishes its variable-speed alerts as a base code with a sub alarm, and the two lockout entries in that family behave differently from every protection alert underneath them. A protection alert shuts the compressor down for a cutout period and then releases itself. A lockout entry stops the system until power is cycled or the alerts are reset. In cold weather the alerts that accumulate underneath include one for which Trane names low outdoor ambient temperature, below a figure printed in its table, as a possible cause. Applies to: Trane TruComfort variable-speed outdoor units on ComfortLink II communicating controls, including the XV20i heat pump The alert architecture and the two lockout behaviours described here are read from Trane variable-speed outdoor unit Service Facts. Pressure thresholds, cutout times and the shutdown count that triggers the lockout are model specific and are printed in the Service Facts for the exact outdoor model, so treat those figures as something to look up rather than to carry across. Owner-safe checks: Photograph the alert screen and the alert history in order, with the display text beside each number. | Record the outdoor temperature and the time at each stoppage, because the protection alerts underneath are tied to operating conditions. | Check whether auxiliary or emergency heat is holding the house, which tells a technician what the system fell back to. Qualified technician: Charge assessment, pressure transducer checks and expansion valve diagnosis are qualified service work on a sealed refrigerant circuit. | Any inspection inside the outdoor cabinet on a variable-speed unit involves stored energy in the drive and belongs to a technician.
Trane furnace burner lights then shuts off: reading the flame sense fault
When a Trane furnace lights its burner and shuts down a few seconds later, the control has decided it cannot confirm the flame it just created. Trane treats that as a flame sensing condition. The burner did light, so the ignition side worked, and what failed was the proof step that keeps the gas valve open. Applies to: Trane gas furnaces whose integrated control proves flame by rectification, as described in Trane homeowner support for a burner that shuts off after ignition Trane support describes this behaviour for gas furnaces whose control proves flame by passing a small current through it. Trane also sells equipment where the same symptom has a different cause, and any numeric or flash code shown on your control is read from that model's own literature rather than from this description. Owner-safe checks: Listen to a complete heating call and note whether the burner lights at all, and how many seconds it stays alight. | Count how many calls succeed and how many fail over two or three days, including the time of day for each. | Replace a loaded filter with the specified clean one, since restricted airflow produces a different fault that can be confused with this one. Qualified technician: Measuring the flame signal in microamps, cleaning or repositioning a sensing electrode, and testing the ground path are licensed gas-furnace tasks. | Do not attempt to clean a sensing rod yourself. It sits in the burner compartment beside live components and a gas train, and an abrasive left on the surface makes the fault worse.
Trane overflow switch shutdown: cooling stops and nothing looks broken
An overflow switch on a Trane air handler interrupts the cooling call when condensate rises past the level it watches. The outdoor unit stops, the thermostat still shows a call, and nothing inside the house looks wrong. That combination is the switch doing its job: it stops the system before water reaches the ceiling below. Applies to: Trane air handlers and indoor coils fitted with a condensate overflow switch, as described in Trane homeowner support Overflow switches are fitted in several positions, including the primary pan, the secondary pan, and in the drain line itself, and not every Trane installation has one. Which switch tripped and how it is wired depends on the installation rather than on the model, so the answer comes from the installer's arrangement as much as from Trane literature. Owner-safe checks: Confirm the thermostat is calling for cooling and that no breaker or fuse serving the indoor or outdoor unit has operated. | Look into any visible drain pan beneath the indoor unit and note whether it holds water or shows a waterline stain. | After the system has been asked to cool for a while, go and look at where the drain discharges outside and see whether anything came out. Qualified technician: Clearing a condensate drain line, testing an overflow switch, and correcting drain fall or trap arrangement are service tasks on this equipment. | Never bypass or unplug an overflow switch to restore cooling. It is the only thing standing between a blocked drain and water in the structure below.