Ruud U802VA050317MSA Error Code A116_F: One-hour Lockout: Flame Presence Alarm
What Does Code A116_F Mean?
Code A116_F is the one-hour lockout state the Ruud U802VA enters after its IFC detects an undesired flame — flame sensed while the board has commanded the gas valve closed. The Bluetooth Communicating IFC reads flame through a flame-rectification sensor and expects a flame signal only while it is energizing the gas valve relay, so a flame signal with the valve off is a flame-presence alarm.
A detail specific to this fault on the U802VA is the timing: the one-hour lockout period commences only after flame is no longer detected. In other words, the control will not start counting down its one-hour wait while an uncommanded flame is still burning — it holds the alarm until the flame is actually gone. This is why A116_F should be read as the escalated, latched form of the underlying A014_F and A127_F "flame present with gas valve off" condition rather than a routine timed lockout.
The most likely cause is a gas valve that is stuck or leaking and continues to feed gas that burns after the valve should have closed; a flame-sensing circuit producing a false flame reading is also possible. Because a valve that will not seal is a gas and carbon-monoxide hazard, clearing the lockout by cycling power does not address the root cause and can restart a furnace whose valve still cannot close. The manual gas supply should stay off until the valve is professionally verified.
What You'll Notice
- The contractor app or IFC shows A116_F and the furnace will not start a heat cycle
- Burners were seen staying lit after the heat call ended, before the lockout latched
- The furnace stays locked out and does not resume even after long periods
- A gas odor near the furnace if the valve is genuinely not sealing
- The related A014_F or A127_F undesired-flame codes appeared before this lockout
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Stuck or leaking gas valve | Most common | ✗ Call a pro → |
How This Is Diagnosed
A technician treats A116_F as a latched flame-presence alarm and focuses on why flame was present with the valve commanded off. They confirm whether real flame lingered after the valve was de-energized by observing the burners during a controlled test, then verify the gas valve fully seats and does not pass gas when off. They also check the flame-sensor microamp signal and wiring for a false-flame reading and inspect the IFC's gas-valve relay circuit for a welded-contact fault that would keep the valve powered. This diagnosis covers the gas valve, sensing circuit, and control board and is informational only, not a homeowner procedure.
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:
- A116_F is displayed, since a latched flame-presence lockout means an uncommanded flame was detected
- There is any smell of gas near the furnace, in which case leave immediately and call your gas company first
- The lockout clears on power-up but the furnace re-locks or the flame codes return
- A014_F or A127_F were logged before the lockout, pointing to the same undesired-flame condition
Frequently Asked Questions
Why hasn't the one-hour lockout timer started counting down?
On this furnace the A116_F one-hour period only begins after flame is no longer detected. If an uncommanded flame is still burning, the control holds the alarm and will not start its countdown, which is a deliberate safety behavior.
Can I wait out the hour and let the furnace restart itself?
You should not rely on that. The lockout is a symptom of flame detected with the gas valve off, which can mean the valve is not sealing. Shut off the manual gas supply and have a technician confirm the valve before allowing any restart.
How does A116_F relate to A014_F and A127_F?
They are the same underlying undesired-flame condition. A014_F and A127_F flag the flame-present-with-valve-off event, and A116_F is the one-hour lockout the control latches into as a result.
✓ Verified against manufacturer service manual — March 2026