Bryant 340MAV Error Code 11: No Previous Code
What Does Code 11 Mean?
The Carrier integrated furnace control on the Bryant 340MAV stores the most recent status code in memory so technicians can review recent diagnostic history. Code 11 indicates that memory is empty — no fault codes have been logged in the last 72 hours.
Status codes are automatically erased after 72 hours. Stored codes can also be cleared when 115VAC or 24VAC power is interrupted, either by turning off the disconnect switch during troubleshooting or by a brief power outage. If you previously saw a different fault code and then cycled power, the stored code will be cleared and code 11 will appear on the next LED readout.
If you are troubleshooting an intermittent problem and see code 11, the fault may have cleared before you checked. Run the furnace through a complete heating cycle and read the LED code immediately after any abnormal behavior to capture the fault before it clears. This is why an intermittent code 31 or 34, for example, can be missed if you wait too long to read the board.
What You'll Notice
- Reading the control board's stored status shows code 11 (one short flash, one long flash) instead of a numbered fault code
- The furnace is otherwise running or idling normally with no active problem
How This Is Diagnosed
Code 11 is read from the control board's stored-status memory and treated as a clean slate — it confirms no fault has been logged in the last 72 hours. When chasing an intermittent complaint, a technician runs the furnace through full cycles and re-reads the LED right after any misbehavior, before the 72-hour window closes or a power interruption erases the code.
- You suspect an intermittent fault but the board keeps showing code 11 because the fault clears before you can read it
- The furnace misbehaves during a cycle but no numbered code is ever captured
Frequently Asked Questions
I saw an error code yesterday but now it shows 11 — did it fix itself?
Not necessarily. Stored codes clear automatically after 72 hours or whenever power is cycled, so an intermittent fault can disappear from memory. Watch for the fault to recur and read the code immediately.
Do I need to do anything about code 11?
No. Code 11 means the fault memory is empty, which is a normal, healthy status.
✓ Verified against manufacturer service manual — March 2026