Carrier 58MVP Error Code 22: Abnormal Flame-Proving Signal
What Does Code 22 Mean?
Status code 22 on the Carrier 58MVP is an abnormal flame-proving signal: the control detects a flame while the gas valve is de-energized (commanded closed). Per Carrier's guide the inducer runs until the fault clears, continuously venting the heat exchanger. The two listed causes are a leaky gas valve and a stuck-open gas valve.
This is a safety-critical condition. If the valve is passing gas after it should have shut, unburned or burning gas can be present when the furnace should be off. The 58MVP responds by keeping the inducer running to move any combustion products out of the vent. It is different from code 21 (a valve wiring or relay lockout) and from the ignition codes 14 and 34, because here flame is present when it should not be.
A leaking or stuck-open gas valve is a professional, safety-critical repair. Do not attempt gas valve work; have it addressed promptly.
What You'll Notice
- The inducer (draft) motor keeps running even when the furnace should be off
- The furnace behaves abnormally around shutdown, with the board flashing code 22
- A faint gas odor is possible if the valve is passing gas
- The furnace does not return to a normal idle state
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Leaky gas valve | Most common | ✗ Call a pro → |
| Stuck-open gas valve | Common | ✗ Call a pro → |
How This Is Diagnosed
A technician confirms whether flame or gas is actually present with the valve commanded off, then tests the gas valve for internal leakage or a stuck seat and checks the flame-sense circuit for a false signal. If the valve is passing gas, it is replaced. All of this is gas-side, safety-critical work performed only by a professional.
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 inducer runs continuously and the furnace will not settle into a normal idle state
- You smell gas at any time — leave the home first and call your gas company
- The board repeatedly flashes code 22
Frequently Asked Questions
Is code 22 on a Carrier 58MVP dangerous?
It can be — it indicates the control senses flame when the gas valve should be closed, which suggests a leaking or stuck-open valve. Get a technician promptly, and if you smell gas, leave and call your gas company.
Why does my inducer keep running with code 22?
The 58MVP deliberately keeps the inducer running to purge the heat exchanger and vent while this fault is present. It is a safety response, not a separate fault.
Sources
✓ Verified against manufacturer service manual — March 2026