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Trane Furnace Error Codes

Error Codes What this means How to fix it
Slow flashing LED light This means that your furnace is on, but it’s not calling for heat. This is only an issue if you have raised your thermostat and your furnace doesn’t respond.
Rapidly flashing LED light Means that your furnace is on and is actively calling for heat. Only beware this if your furnace is continuously calling for heat and isn’t responding to your thermostat.
Continuous LED on Control panel issue. Replace the control panel.
Two LED flashes System lockout due to lack of flame or reversed polarity. Check for miswiring, clogged pilot tube, or humidity in the unit.
Three LED flashes Draft pressure error. Check if the drain tubes are full of moisture or obstructed with dirt.
Four LED flashes The furnace is experiencing an open temperature limit circuit issue. The issue with thermal protection.
Five LED flashes A flame was sensed within your furnace that shouldn’t be present. Check for a leaky gas valve, stuck gas valve, or defective flame sensor.
Six LED flashes AC power voltage is too low. Correct line voltage polarity, check the wiring.
Seven LED flashes An issue with your gas circuit. Check your unit’s gas valves for the issue.
Eight LED flashes Low Flame. Check for flame sensor malfunction or low gas pressure.
Nine LED flashes Igniter circuit issue. Check igniter.
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