Aaon Air Handler Troubleshooting
Aaon air handlers are known for their efficiency and dependability. Although problems with these units aren’t common, this Aaon air handler troubleshooting guide will help you identify and resolve issues with your unit quickly and easily.
These instructions are for H2 and V2 air handler models. Any testing or repairs outlined in this guide will need to be completed by an authorized technician.
Evaporator Coil Is Frozen, Low Suction Pressure
- Airflow is restricted - Clean or replace the filters.
- Fan speed is low - Check the fan drives.
- Reversed blower rotation - Correct the wiring.
- Refrigerant charge is low - Add refrigerant.
Unit Is Blowing Hot Air
- Refrigerant is leaking - Check for leaks and add refrigerant if necessary.
- Expansion valve element is faulty - Replace the defective valve element.
- Filter-drier is clogged - Replace the filter-drier.
Compressor Starts, But Opens High Pressure Control
- Refrigerant is overcharged - Remove some of the refrigerant.
- Air is in the condenser coil - Evacuate and then recharge the refrigerant.
- Condenser fan is faulty - Replace the defective fan motor.
- Condenser coil is dirty - Clean the condenser coil.
High Suction Pressure, But Superheat Is Low
- Expansion valve is oversized - Replaced the oversized valve with an expansion valve of the correct size.
- Sensing bulb location isn’t optimal - Move the sensing bulb to an optimal location, making sure to secure the bulb to the suction line.
- Superheat adjustment is low - Adjust the expansion valve.
Unit Runs Continuously
- Refrigerant charge is low - Check and recharge the refrigerant to the nameplate.
- Unit is undersized - Decrease the load or resize the unit.
- Thermostat is set too low - Increase the temperature setting.