Brand: MITSUBISHI ELECTRIC
Category: Air Conditioner
Document Type: Manual
Language: EN
Manual for OBH702
Uploaded: Nov. 21, 2025, 6:21 p.m.
Manual Publish Date: 2014-09-01
Warranty Information
Specifications are subject to change without notice.
Preparation Before Repair Service
- Prepare proper tools and protectors.
- Ensure adequate ventilation.
- Turn off the power-supply breaker and pull the power plug after stopping the air conditioner operation.
- Discharge the capacitor before working on electric parts.
Precautions During Repair Service
- Do not perform work on electric parts with wet hands.
- Do not pour water into electric parts.
- Do not touch the refrigerant.
- Avoid touching hot or cold areas in the refrigeration cycle.
- Exercise extreme caution to avoid touching live parts when working without turning off the power.
Refrigerant Handling (R410A)
- Use only the specified R410A refrigerant.
- Ensure piping is clean and free from contaminants.
- Use pipes with specified thickness.
- Apply only a small amount of ester oil, ether oil, or alkylbenzene oil to flare and flange connections.
- Charge refrigerant from the liquid phase of the cylinder.
- Ventilate the room if refrigerant leaks; poisonous gases can be released if refrigerant contacts flame.
Troubleshooting and error codes
| Item | Troubleshooting | Cause | Remedy |
|---|---|---|---|
| No cooling/heating | Outdoor unit fan does not rotate. | 1. Fan motor failure. | Replace the fan motor. |
| 2. Outdoor control P.C. board failure. | Replace the outdoor control P.C. board. | ||
| Indoor unit does not operate. | 1. Power supply error. | Check the power supply. | |
| 2. Indoor unit P.C. board failure. | Replace the indoor unit P.C. board. | ||
| Insufficient cooling/heating capacity. | 1. Refrigerant leak. | Find and repair the leak, then charge the correct amount of refrigerant. | |
| 2. Indoor/outdoor unit dirty. | Clean the filters and coils. | ||
| 3. Fan motor failure. | Replace the fan motor. | ||
| Noise during operation. | 1. Loose parts. | Tighten loose parts. | |
| 2. Fan unbalanced. | Replace the fan motor. | ||
| Compressor does not operate. | 1. Compressor failure. | Replace the compressor. | |
| 2. Overload protector tripped. | Check for causes of overload and reset. | ||
| 3. Outdoor control P.C. board failure. | Replace the outdoor control P.C. board. |