Carrier 58MVC Furnace Error Code 14: Ignition Lockout
What Does Code 14 Mean?
An ignition lockout means the variable-speed control board gave up after repeated failed attempts to light the burners and confirm a flame. Code 14 is the lockout that follows the active ignition-proving fault reported as code 34: the control tries to ignite, fails to sense flame, retries, and after the allowed attempts it locks out and auto-resets after 3 hours.
Because code 14 only appears after the furnace has already cycled through its ignition retries, the earlier warning sign — code 34 — has typically already fired. The flame-sensor-cleaning guidance for that earlier, still-recoverable fault lives on the code 34 page; if you have not tried it yet, that is worth checking first. But once the furnace reaches a hard code 14 lockout, a simple sensor cleaning has effectively already had its chance to resolve the problem, which is why this stage calls for professional diagnosis rather than another cleaning attempt.
Common causes a technician investigates are a gas supply problem — a closed manual gas valve or low gas pressure — a failing hot surface igniter that no longer gets hot enough to light the gas, and a flame-sensing circuit that is not reading a reliable signal. On this condensing, step-modulating furnace, ignition happens on the low-heat stage first, so a weak igniter or a marginal flame signal shows up here before the furnace ever steps up to medium or high heat.
Testing or replacing the igniter, measuring gas pressure, and diagnosing the flame-sensing circuit or gas valve require a technician's tools and training.
What You'll Notice
- The igniter glows and the burners may light briefly, then the furnace shuts down
- You hear several ignition attempts (clicks or the inducer cycling) before it stops trying
- No heat for up to 3 hours while the board sits in lockout
- Cold air or no airflow when the thermostat is calling for heat
- The problem often appears at the start of the heating season after months idle
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Dirty flame sensor | Most common | ✗ Call a pro → |
| Gas supply turned off or low gas pressure | Common | ✗ Call a pro → |
| Defective hot surface igniter | Common | ✗ Call a pro → |
How This Is Diagnosed
A technician works from the same fault chain the board reports: they first confirm gas supply is present at the correct pressure, then check the flame-sensing circuit — including the sensor rod's condition and its microamp signal — since a degraded signal is a frequent contributor to repeated ignition-proving failures. They also test the hot surface igniter's resistance and glow, and check the wiring and control board for other explanations. Because code 14 is a hard lockout that follows failed retries, the goal is to find why relighting kept failing, not just to clear the code.
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 shows code 14, since this lockout follows failed ignition retries and needs a technician's diagnosis
- The igniter does not glow at all, or glows but the gas never lights
- You smell gas or see soot around the burners
- Code 34 has already appeared and a flame-sensor cleaning did not stop the lockouts
Frequently Asked Questions
How do I reset code 14 on a Carrier 58MVC?
The control auto-resets after about 3 hours, or you can reset it immediately by turning the furnace power switch off for a moment and back on. But it will lock out again unless the ignition problem is fixed.
What most often causes code 14 on the 58MVC?
The manual doesn't single out one cause; a technician typically finds a gas supply issue, a failing igniter, or a flame-sensing problem that let ignition keep failing until the lockout tripped. Because code 14 follows the failed retries reported as code 34, a technician diagnosis is the right next step rather than another DIY attempt.
Is it safe to keep resetting an ignition lockout?
Resetting once to test a fix is fine. Repeatedly forcing the furnace to retry without addressing the cause is not a good idea, especially if you smell gas — in that case stop and call a professional.
How much does it cost to fix code 14?
It varies widely by region and cause — a service call to diagnose and clear a lockout costs less than an igniter or gas-valve replacement. A technician can give an exact quote once they've found which component failed.
✓ Verified against manufacturer service manual — March 2026