Fraser-Johnston
Short Cycling / Control or Capacity Issue
The air conditioner short cycles (turns on and off frequently).
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Possible Causes
Oversized Fraser‑Johnston system, Thermostat located near a supply register, Low refrigerant charge, Faulty thermostat or control board
How to Fix / Troubleshooting
Safety: Turn off power before moving thermostat wiring.
- Check thermostat location: Ensure the thermostat is not directly in the path of supply air or near heat sources. Relocate if necessary.
- Verify thermostat settings: Disable any aggressive energy-saving cycles that may cause short cycling.
- Filter and coil check: Clean filters and coils to ensure proper airflow.
- Professional evaluation: If short cycling persists, have a technician check the refrigerant charge and system sizing.
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Repair Difficulty
Easy
2/5
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