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Identifying the refrigerant and taking flammable-refrigerant precautions on a non-sealed-system repair

Read the label first. R-600a and R-290 are highly flammable (A3); R-32 and R-454B are mildly flammable (A2L). You can still do electrical and airflow repairs, but use exact OEM electrical parts, keep sharp tools and ignition sources away from tubing, and refer anything that opens the refrigerant circuit.

Cross-checked ~10 min easyBrands: All

Before you start

No open flame, torch or smoking near the unit.
Never pierce, cut, braze or charge the refrigerant circuit: EPA 608 work, blocked.

Diagnostic steps

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OnCall Tech is a reference tool for trained technicians and can make mistakes. Always disconnect power and confirm with the manufacturer's documentation before you work.

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