Bradford White heat pump (hybrid) water heater shows E30 and disables heat pump mode.

Safety: Turn off power at the breaker. Components in the heat pump section may have sharp edges; wear gloves.

Steps:

• Access heat pump compartment: Remove the top cover per Bradford White instructions to expose the evaporator coil and sensors.
• Locate sensor: Find the evaporator temperature sensor clipped to or near the evaporator coil tubing.
• Inspect and reseat: Check the sensor wiring for damage. Unplug and replug the connector at the control board to ensure a solid connection.
• Test sensor: Measure resistance at room temperature and compare to Bradford White thermistor chart. Replace the sensor if readings are open, shorted, or far off spec.

If the error persists with a known-good sensor, the main control board may be defective and require replacement by a technician.