Chiller Repair in Mountain View — OC2 Error Fixed, Refrigerant Replaced with R-422

Commercial HVAC / Chiller Diagnosis and Repair

A commercial chiller was serviced due to unstable operation and repeated shutdowns caused by an OC2 error code. The system was entering protection mode, indicating a refrigeration circuit issue rather than an electrical fault.

Equipment:
Brand: Dawon
Model: DS-1500

During inspection, the issue was identified as a technically connected chain of failures rather than a single error:

• ✅ Critically low refrigerant level
• ✅ Loss of proper heat transfer efficiency
• ✅ Increased discharge temperature
• ✅ Compressor overheating
• ✅ OC2 protection triggered to prevent mechanical damage
• ✅ High risk of compressor failure if operation continued

Why R-22 Is No Longer Used

R-22 has been fully phased out in the United States due to environmental regulations related to ozone depletion. Its production and import are prohibited, and remaining stock is extremely limited and economically impractical for commercial HVAC systems.

Continued operation on R-22 or partial refrigerant top-offs leads to unstable performance, excessive compressor load, frequent shutdowns, and a significantly increased risk of major mechanical failure.

Repair and Refrigerant Conversion

To restore stable operation and comply with current regulations, a technically correct refrigerant conversion was performed:

• ✅ Full recovery and removal of remaining refrigerant
• ✅ Deep system evacuation to remove moisture and non-condensable gases
• ✅ Recharge with R-422, a compatible replacement for R-22
• ✅ Verification of operating pressures, temperatures, and compressor amperage
• ✅ Performance testing under operating load

R-422 provides operating characteristics close to R-22 and allows continued use of existing system components without compressor replacement or major system modification.

Cost

The scope of work included refrigerant, refrigeration circuit service, system startup, and final verification. Total cost — under $900.

Recommendation

If a commercial HVAC or chiller system was originally designed for R-22, delaying refrigerant replacement inevitably leads to overheating, repeated fault codes, and expensive compressor damage. When pressure, temperature, or protection errors appear, the correct solution is not adding refrigerant but performing a full, controlled conversion.

This type of work should be handled by experienced professionals such as ABC Service, ensuring regulatory compliance, stable operation, and long-term equipment reliability.