AirQuest Error Code 13: Limit circuit lockout (Furnace)
AirQuest error code 13 on a furnace means: Limit circuit lockout. It is also called AirQuest diagnostic code 13.
Homeowner? What AirQuest code 13 means for you
Call a technician Your furnace is reporting: Limit circuit lockout. The furnace has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.
Safe things you can check yourself
- Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
- Make sure the unit has power: its on/off switch (often looks like a light switch near the unit) is ON and the breaker in the electrical panel is not tripped.
- Make sure the furnace front door or panel is closed properly; many furnaces will not run with the door switch open.
- Look at the air filter. If it is grey and clogged, replace it; a blocked filter causes many shutdowns.
- Outside, make sure the intake and exhaust pipes or vent cap are not blocked by snow, ice, leaves or a nest.
- Check that the gas valve next to the furnace is open (handle in line with the pipe). Do not force it.
- Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.
Call (647) 657-2977Book a service call
Licensed technicians serving Vaughan, Toronto and the GTA.
What does AirQuest error code 13 mean?
The limit circuit opened too many times; the control is in lockout.
Applies to: Carrier/ICP-family two-digit status codes — confirm with the code label on the unit
Common causes of AirQuest code 13
- Dirty filter / restricted airflow
- Closed supply registers
- Blower not running or wrong speed tap
A technician checks these and 2 other possible causes on site before replacing any part.
Other AirQuest Furnace codes
| Code | Meaning |
|---|---|
| 14 | Ignition lockout |
| 31 | Pressure switch did not close or reopened |
| 33 | Limit circuit fault |
| 34 | Ignition proving failure |
All AirQuest Furnace error codes →
AirQuest code 13: homeowner questions
What does AirQuest code 13 mean?
Limit circuit lockout. The limit circuit opened too many times; the control is in lockout.
Is it safe to keep using my furnace with code 13?
It depends on the cause. The furnace has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.
Can I reset AirQuest code 13 myself?
You can try one reset (power off for 30 seconds, then on). If AirQuest code 13 comes back, the cause is still there and a licensed technician should check it.
Who can fix AirQuest code 13 near me?
Aurora Star Tech Inc. repairs AirQuest furnaces in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.
Homeowner help: Furnace Not Turning On: What to Check · Furnace Blinking Light: What the Flash Codes Mean
Troubleshooting guides
- Blowing cold air All brands · Furnace
- No heat All brands · Furnace
- Short cycling All brands · Furnace
Source: Carrier/ICP status code label — verify per model. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.