How to reset air handler?

Resetting your residential indoor air handler involves performing a complete electrical power cycle to clear temporary control board lockouts, communication errors, or safety switch trips. First, go to your indoor wall thermostat and switch the system mode setting to "Off" to halt any active heating or cooling control signals. Second, go to your home's main electrical service panel and locate the circuit breaker switch dedicated specifically to your indoor air handler or furnace. Third, flip the circuit breaker fully to the "Off" position. Fourth, wait a mandatory minimum of five full minutes to allow internal control board capacitors, relays, and low-voltage transformers to fully discharge and reset. Finally, switch the circuit breaker back to the "On" position, wait a moment for the system to boot up, and adjust your thermostat. You can verify success when normal blower operation resumes.