Technical troubleshooting guides, fault code explanations, and diagnostic help for Trane HVAC systems — from Thomas Hoffmann Air Conditioning & Heating in St. Louis.
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 …
The capacitor is one of the most commonly failed components in a Trane air conditioner or heat pump — and fortunately, one of the most affordable and quickest to repair. A failed capacitor can prevent the outdoor unit from starting, cause the compressor to run inefficiently, or leave the condenser fan stopped while the compressor …
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 …
Trane thermostats — including the XR402, XL824, XL850, and older TCONT series — are reliable controls, but when they stop responding or display errors, they can prevent your entire HVAC system from operating. This guide walks through the most common Trane thermostat problems, what causes them, and what you can fix yourself versus what requires …