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Blower runs nonstop and no cooling on a new HVAC system: A2L refrigerant leak sensor

A2L systems carry a refrigerant leak sensor near the indoor coil. When it reports a leak, or when the sensor fails or loses communication, the control stops the compressor and runs the blower to dilute any refrigerant. This guide separates a sensor or wiring fault from a possible real leak; any real leak is referred to an EPA 608 technician.

Cross-checked ~40 min moderateBrands: All

Before you start

  • Treat a mitigation event as a possible real leak until proven otherwise: ventilate, no open flames or sparks near the indoor unit.
  • Never unplug, bypass or relocate the leak sensor to make the system run.
  • Leak search and refrigerant repair are EPA 608 work: blocked, refer.

Diagnostic steps

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Blower runs nonstop and no cooling on a new HVAC system: A2L refrigerant leak sensor · OnCall Tech