Trane products, including furnaces and air conditioners, are some of the most reliable on the market. However, that doesn’t mean they don’t have problems.
To help you determine what’s going wrong with your Trane furnace, let’s take a look at some of the most common error codes.
What does a red blinking light on a Trane furnace mean?
Like many other top furnace brands, Trane uses a red blinking light to communicate error codes. A red blinking light can mean different things. The meaning is determined by the number of times the red light blinks, as well as how fast it is blinking.
Here are some Trane furnace error codes you might encounter.
| Trane Furnace Error Code | Meaning | Potential Issue |
| Constant slow blinking | Furnace is functioning normally | |
| Constant fast blinking | Furnace is functioning normally | |
| Red light constant ON | Control failure | Control panel issue |
| Red light constant OFF | Check Power | Power off |
| 2 blinks | Flame failure (retries exceeded) | Gas supply issue, flame rod not sensing flame, wiring issue, etc. |
| 3 blinks | Pressure switch problem | Blockage in vent, condensate drain plugged, etc. |
| 4 blinks | Temperature switch problem / Over temperature limit | Plugged filter, plugged secondary heat exchanger, ductwork issue, etc. |
| 5 blinks | Flame sensed when no flame should be present | Leaky gas valve, stuck gas valve, defective flame sensor, etc. |
| 6 blinks | 115 VAC power reversed polarity, poor grounding | Issue with line voltage polarity or wiring, etc. |
| 7 blinks | Gas valve circuit error | Gas valve issue |
| 8 blinks | Low flame sense signal | Flame sensor malfunction, low gas pressure, etc. |
| 9 blinks | Check igniter | Check igniter |