Primary causes of nuisance tripping automatic limits are:

- Insufficient air flow (see label on heater’s door for airflow minimums). Make sure airflow meets minimum and pressure differential is met.
 - Improper installation, i.e. too close to a fan, damper, elbow/turn, transition
  (4ft minimum). Move the heater further downstream from the device causing turbulence. If moving the heater is not possible, air straighteners or pressure plates (perforated sheet steel) can be installed upstream of the heater to reduce the turbulence at the heater.

- Incoming air temperature too high – IAT of 110°F or higher can cause issues.