Carrier · Status code
Carrier 59TN7A status code 14: flame-loss lockouts during a heat request
Major code 14 records repeated flame or draft losses during one heating demand. Minor 14.2 means flame was lost three times after roughly 70 seconds of heating; 14.3 means seven flame-loss events accumulated during a heat request and the control locked out; 14.4 means the low-heat (main) pressure switch LPS opened seven times during a heat request and the control locked out.
On the control
- Code
- 14
- Minor
- 14.2 · 14.3 · 14.4
- Door LED
- 1 short flashes then 4 long
- Controller
- 59TN7A integrated furnace control with 3-digit LCD display and door LED
- Applies to
- Carrier Infinity 97 (59TN7A)
- Manual
- 59TN7A-01SI
What each minor code says, verbatim
| Display | Manufacturer wording |
|---|---|
| 14.2 | Flame lost 3 times after 70s of heating |
| 14.3 | Lockout - 7 loss of flame events during a heat request |
| 14.4 | Lockout - 7 pressure switch open events during a heat request |
A code is a condition, not a diagnosis
Flame loss mid-cycle (14.2, 14.3) is not the same as a failed ignitor: the burner lit and then the flame signal stopped. Fouled flame sensors, flame disturbance from combustion-air or venting problems, gas-pressure fluctuations, condensate flooding, or intermittent electrical connections all produce it. 14.4 points at the draft side: the LPS opened while the inducer was running, which traces to venting, condensate, the inducer, tubing or the switch itself.
Which furnaces this applies to
Documented for Carrier 59TN7A furnaces (all nine sizes) in installation instructions 59TN7A-01SI REV A, edition 06/23. The 14.4 sub-code is specific to two-stage controls that monitor the main pressure switch throughout the run.
Scope: Carrier 59TN7A Infinity 97 furnaces with the on-board 3-digit display control. Not sure which control you have? Send us the full model number from the rating plate.
Safe things to look at first
- Read the full code on the control display through the door, including any minor digit (for example 33.2), and write it down.
- Look, without touching, for obvious conditions you can report: snow or ice at the vent terminations, water on the floor, a loaded filter, a condensate pump that is full or off.
- Note whether the furnace still heats at all, and how long it runs before the code returns.
- Note whether the code appears minutes into a cycle (mid-run flame loss) or immediately (start-up failure), and whether the furnace relights between events.
- Check the vent and intake terminations for snow, ice, leaves or a nest, and the floor around the furnace for water.
Do not
- Do not bypass or jumper the door switch, limit switches, rollout switches or pressure switches.
- Do not open the burner compartment, disconnect tubing, or adjust the gas valve or gas pressure.
- Do not keep cycling power to force the furnace to relight; repeated resets hide the fault and can allow unburned gas to build up after ignition failures. If the code returns, stop and call.
Homeowner-safe checks (look and read only)
- Note whether the code appears minutes into a cycle or at start-up
- Check the vent and intake terminations for snow, ice or a nest
- Check the floor around the furnace for water
When to call a technician
- If the furnace relights and drops out repeatedly
- If you smell gas at any point
Also documented on the same controller family: Carrier Performance 97 (59TP7A).
What a technician does
- A technician measures flame signal with the furnace running, inspects the flame sensor and burner area, checks gas supply pressure, and reviews the stored fault history for how the events accumulated.
- For 14.4 the venting, condensate path, inducer performance and pressure-switch tubing are tested with a manometer.
Same code, other equipment
- Older Carrier controls: Code sets differ on earlier Carrier furnaces; confirm the family code on the rating plate before comparing.
Related components and symptoms
Questions people ask
Flame keeps going out after the furnace runs a while. What causes that?
The usual suspects are a fouled flame sensor, condensate interfering with the flame-sensing circuit, venting that starves or pressurizes combustion, or an intermittent gas supply. The control logs the events; a technician reads the history and tests each cause.
Is code 14.4 the same as code 32?
Both involve the main pressure switch LPS, but 14.4 counts seven LPS-open events during one heat request and locks out, while code 32 documents the switch state at a specific moment. On this control, 32.2 means the LPS is open when it should be closed.
Seeing code 14 on your Carrier?
Tell us the full code, the model number and whether the furnace still heats on low. BC Wide prioritizes no-heat calls across Greater Vancouver.