Bryant 340MAV Error Code 14: Ignition Lockout
What Does Code 14 Mean?
Status code 14 on the Bryant 340MAV is an ignition lockout. The Carrier integrated furnace control made repeated attempts to ignite the burners and prove a flame, and all attempts failed. The control locks out to prevent further unsuccessful ignition attempts and auto-resets after 3 hours.
The service documentation directs troubleshooting to code 34 (ignition proving failure), which is the active fault recorded each time an ignition attempt fails. Code 34 tries three more times before it rolls up into this code 14 lockout, so the two codes describe the same event at different stages: 34 is the active failure, 14 is the accumulated lockout.
The three most common causes are a dirty or faulty flame sensor, a defective hot surface igniter, and a gas supply issue or defective gas valve. Because clearing this fault involves the flame sensor, igniter, gas valve, and gas pressure, it is diagnosed and repaired by a technician rather than reset repeatedly.
What You'll Notice
- The furnace tries to light several times, then goes quiet with no heat produced
- You hear the igniter and inducer cycle repeatedly, then everything shuts down for a long period
- The burners may light briefly and then drop out, after which the furnace locks out
- No heat is produced and the code persists until the roughly 3-hour auto-reset
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Dirty or faulty flame sensor | Most common | ✗ Call a pro → |
| Defective hot surface ignitor | Common | ✗ Call a pro → |
| Gas supply issue or defective gas valve | Common | ✗ Call a pro → |
How This Is Diagnosed
Because code 14 is the lockout that accumulates from repeated code 34 failures, diagnosis follows code 34. A technician typically inspects the flame sensor for oxide buildup first (the most common cause), then tests the hot surface igniter's resistance and confirms it glows, and verifies gas is on with correct manifold pressure. The flame-sense microamp signal and the control ground are checked as well. Once the underlying cause is corrected, the lockout clears on the next auto-reset or a power cycle.
When to Call a Professional
This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:
- The furnace relocks out with code 14 after the three-hour auto-reset
- The burners light but drop out after a few seconds on each attempt
- The igniter does not glow, or you hear gas but there is no ignition
- Code 34 keeps recurring alongside the lockouts
Frequently Asked Questions
My Bryant 340MAV lit a few times then quit with code 14 — why?
The control locks out after several failed attempts to light or prove a flame. A dirty flame sensor is the most common reason it lights and then drops out; the igniter or gas supply can also be at fault.
Will code 14 clear on its own?
The control auto-resets after about three hours, but if the cause is not fixed it will fail again and relock. It needs a technician to correct the ignition problem.
✓ Verified against manufacturer service manual — March 2026