Display shows FrE or FREEZE; system runs unexpectedly at low temperatures or locks out solar heating.

Safety: Do not disable freeze protection in climates where freezing is possible unless the system is fully winterized.

• Verify actual temperature: Compare the controller's displayed temperature to a reliable thermometer. If the reading is much lower, the sensor may be faulty or poorly located.
• Check sensor placement: Ensure the freeze or roof sensor is not mounted in a shaded, wind-exposed area that gets much colder than the panels themselves.
• Adjust freeze setpoint: In the controller menu, confirm the freeze protection temperature is appropriate for your region. Do not set it so high that FrE triggers unnecessarily.
• Inspect wiring: Look for damaged or shorted sensor cables that could cause false low readings. Repair or replace as needed.
• Winterize if disabling: If you choose to disable freeze protection for service, first drain and isolate the Fafco panels and exposed plumbing to prevent freeze damage.