H3 TROUBLESHOOTING STEPS:

DISCONNECT POWER TO OUTDOOR UNIT

STEP 1: Evaluate the Installation​

TIPS:

• H3 indicates the external temperature Overload Protection Switch on the Compressor has opened (overheated), caused by factors like low charge, overwork from restriction, dirty condenser, etc.

• Check if indoor filters, coil, and blower wheel are clean.

• Inspect the cleanliness of the condenser and ensure adequate space for airflow in both indoor and outdoor units.

• Confirm that all service valves are open, and the unit was properly evacuated below 500 Microns.

• For MULTI-zone units, ensure wiring and linesets match the correct ports outside for each indoor unit.

• Check if additional charge was required, following piping rules in installation instructions.

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STEP 2: Check Standing Refrigerant Pressure​

TIPS:

• Connect gauges to the outdoor service port. Standing pressure should be equal to outdoor ambient temperature. See PT Chart.

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RESTORE POWER TO OUTDOOR UNIT

STEP 3: Turn System On (Cool or Heat Mode)​

TIPS:

• Check if the outdoor unit operates.

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IF THE OUTDOOR UNIT IS NOT OPERATING

STEP 4: Check Compressor - Is it hot?

• Disconnect the Molex Plug for the overload switch at the control board and ohm across the wires. The resistance reading should be close to zero ohms.

• If OL (open line) is read, disconnect wires from the overload at the compressor and check the resistance across the overload itself. If the reading is still OL and the compressor is cool to the touch, the overload has failed.

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STEP 5: If Overload Proves Good

• Jump out the overload connection at the board and reapply power to check operation. If the outdoor unit still does not operate, replace the main board.

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STEP 6: In Cooling Mode (If Delta T or Low Pressures Indicate Lack of Refrigerant or Restriction):

• Recover and weigh out the charge, perform a triple evacuation, and weigh the proper charge back in.

• Follow refrigerant temperatures by performing a 4-point temperature check.

TIPS:

• For MULTI-zone units, ensure wiring and linesets match the correct ports outside for each indoor unit.

• See 4-Point Temp Check Guide.

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