Run capacitor
Common no-start and weak-compressor failure point. Match the microfarad and voltage rating.
Aprilaire 68 Dehumidifier Fault Codes — Quick Reference
The Aprilaire 68 is a high-capacity whole-home dehumidifier (130 pints/day). It uses an electronic control board that displays fault codes on the unit’s LED status panel.
| Fault Code | Meaning | Quick Fix |
|---|---|---|
| E1 | Freeze protection — coil temperature too low | Check refrigerant charge and airflow |
| E2 | High pressure fault | Check condenser coil cleanliness and airflow |
| E3 | Compressor fault | Check compressor and electrical supply |
| Drain alarm | Drain line backup or float switch trip | Check drain line and float switch |
| Low airflow | Dirty filter or blocked airflow | Replace air filter |
| Sensor fault | Temperature sensor failure | Check sensor and replace |
Most Common Faults
E1 — Freeze Protection
The evaporator coil temperature has dropped below the freeze protection setpoint. The unit shuts down to prevent ice buildup. Causes:
- Dirty air filter — reduces airflow over the coil, causing temperature drop
- Low refrigerant charge — low charge causes evaporator to drop below freezing
- Low room temperature — operating below rated ambient temperature range
- Blocked air return
Fix: Check and replace air filter. Confirm ambient temperature is above 55°F (typical minimum for dehumidifier operation). If filter is clean and ambient is correct, refrigerant charge may be low.
E2 — High Pressure Fault
Discharge pressure is too high. On a dehumidifier, the condenser coils must be clean and have adequate airflow. Check:
- Condenser coil — clean with soft brush or compressed air
- Airflow — nothing blocking the discharge air outlet
- Ambient temperature — above maximum rated ambient (typically 80–95°F for dehumidifiers)
E3 — Compressor Fault
The compressor is not running or has tripped on internal protection. Check:
- Power supply — correct voltage (120V or 240V depending on model)
- Compressor thermal overload — allow unit to cool for 30 minutes
- Starting capacitor — test if compressor hums but doesn’t start
- Compressor winding resistance — check with ohmmeter
Filter Maintenance
The Aprilaire 68 requires filter replacement. A dirty filter is the root cause of E1 faults in most cases.
- Filter size: check the model label
- Replace: every 3 months or when fault recurs
Drain System
The Aprilaire 68 can gravity drain or use a condensate pump. If water backs up and the float switch trips:
- Clear the drain line with a wet/dry vacuum
- Flush with diluted bleach solution
- Check that the drain line has adequate slope
Parts Often Needed
| Part | Notes |
|---|---|
| Air filter | Most common maintenance item |
| Refrigerant charge | After confirmed E1 with clean filter |
| Start capacitor | Common on E3 compressor faults |
| Condensate pump | Replace if pump fails to discharge |
Need Replacement Parts?
Before ordering, match the HVAC part to the model number, electrical rating, and failure symptom. Check current prices on Amazon - prices and availability change frequently.
Jump to Fix
- E1 freeze → Replace filter → Check ambient temp → Check refrigerant
- E2 high pressure → Clean condenser coil → Check airflow → Check ambient
- E3 compressor → Allow to cool → Check capacitor → Verify voltage
When to Call a Pro
Refrigerant work and compressor replacement require EPA 608 certification. Contact an Aprilaire dealer for warranty service.