Trane heat pumps provide both heating and cooling from a single outdoor unit, making them an efficient choice for St. Louis homeowners. But when a heat pump stops working properly — especially in heating mode — diagnosing the problem requires understanding how heat pumps work differently from conventional furnaces and air conditioners. This guide covers …
A 3-flash fault code on a Trane furnace indicates a pressure switch fault — specifically, the pressure switch failed to close (or opened unexpectedly) during a heating cycle. This is one of the most common Trane furnace fault codes, and it has several possible causes ranging from a blocked vent (a 5-minute fix) to a …
A 4-flash fault code on a Trane furnace means the high limit switch has opened — the furnace detected that the heat exchanger was getting too hot and shut down the burners to prevent damage. This is one of the most important safety features on your furnace, and it is also one of the most …
The flame sensor is a small but critical component in your Trane furnace — and it is one of the most common causes of furnace problems. A dirty or failed flame sensor causes the furnace to light and then shut off within seconds, usually with a 8-flash fault code (low flame signal) on the control …
Trane gas furnaces use a diagnostic LED on the control board to communicate fault codes through a series of blinks. When something goes wrong, the LED flashes a specific pattern — a number of rapid blinks followed by a pause — that points to the cause of the problem. Understanding what these codes mean can …
Trane air conditioners and heat pumps use a diagnostic flash code system to communicate faults to technicians and homeowners. When your Trane AC stops cooling, short cycles, or refuses to start, the system's control board is often already telling you exactly what went wrong — if you know how to read it. This guide covers …