Trane Error Code 5: Flame Sensed With Gas Off

Severity
Warning
Type
led blink count
Where to look
sight glass
Estimated repair cost: $200 — $500 (parts + labor)
Warning: Your Trane furnace has detected a gas leak safety hazard. Turn off the gas supply and call a professional immediately.

LED Blink Pattern

How to Fix Trane Code 5

  1. Step 1: Turn off the gas supply valve located near your furnace.
  2. Step 2: Do not attempt to operate the furnace until a professional has inspected and repaired the issue.
  3. Step 3: Call a licensed HVAC technician immediately to diagnose and fix the problem.

How to Reset Trane Code 5

  1. Turn off the furnace power switch, usually located on or near the unit.
  2. Turn off the circuit breaker for the furnace. Wait 30 seconds.
  3. Restore power at the breaker and flip the furnace switch back on.
  4. Set the thermostat to call for heat. If the error code returns after 2-3 ignition attempts, the fault requires repair.

Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.

What Does Trane Error Code 5 Mean?

The 'Flame Sensed With Gas Off' error code on your Trane furnace indicates that the gas valve is closed, but the flame sensor still detects a flame. This could be due to a gas leak or a malfunctioning gas valve. It's crucial to address this issue promptly to ensure your safety.

Common Causes

  • A gas leak near the furnace
  • A faulty gas valve that's not closing properly
  • A malfunctioning flame sensor
  • A problem with the gas pressure regulator

Diagnostic Steps

If... Check Expected
You smell gas or see a gas leak Turn off the gas supply valve and call a professional immediately. No gas smell or leak
The gas valve is closed Inspect the gas valve for any signs of damage or malfunction. Gas valve closes properly
The gas pressure is within the manufacturer's specified range Inspect the flame sensor for any signs of damage or soot. Flame sensor is clean and undamaged

Applicable Trane Models

Recall Notices

Trane/American Standard Gas-Electric Packaged Units Recalled Due to Fire Hazard 25-XXX Active

Issued: July 1, 2025

Affected models: Gas-electric packaged units manufactured Jan 2024 - Mar 2025

Fuel gas valve can open unexpectedly, creating gas leak and fire hazard. Stop using heating mode.

View official notice

Replacement Parts

Part OEM Number Est. Cost Where to Buy
Gas Valve Trane 10000-0001
Flame Sensor Trane 10000-0002
Gas Pressure Regulator

Related Codes on Same Models

Other codes that affect the same Trane model families as 5.

Code Description Severity
2 System Lockout Warning
3 Pressure Switch Error Warning
4 Open Limit Switch Warning
6 Polarity/Grounding Error Warning
7 Gas Valve Circuit Error Warning
8 Low Flame Signal Warning
9 Igniter Problem Warning
FAST-FLASH Active Call for Heat Warning
SLOW-FLASH Normal Operation (Standby) Warning
STEADY-OFF No Power Warning