Display shows SE or SEr and spa functions erratically

Safety first: Turn off power at the GFCI breaker before accessing the control pack.

Steps to troubleshoot SE:

• Inspect sensor connections: Open the equipment bay and locate all sensor plugs on the control board. Unplug and replug each one, checking for corrosion or moisture.
• Dry the area: If moisture is present, dry with a clean cloth and allow the compartment to air dry before restoring power.
• Test sensors: Using a multimeter and the sensor resistance chart from the manual, verify that each sensor’s resistance matches the actual water temperature. Replace any sensor that is out of specification.
• Replace sensor set: For persistent SE errors, replace both the primary temperature sensor and high-limit sensor as a matched set.

When to call a technician: If SE remains after sensor replacement, the control board may be defective and should be evaluated or replaced by a professional.