Display shows Prr or PR and spa may not heat or may shut down unexpectedly

Safety first: Disconnect power at the GFCI breaker before servicing pressure components.

Prr/PR indicates the control system is not seeing the expected pressure signal when the pump runs.

• Locate pressure switch: On some American Whirlpool models, a mechanical pressure switch is threaded into the heater manifold with two wires leading to the control pack.
• Inspect wiring and terminals: Check for loose spade connectors, corrosion, or broken wires at the pressure switch.
• Check for flow restrictions: Clean the filter, verify valves are open, and inspect heater unions for debris or scale.
• Test continuity: With power off and pump not running, use a multimeter to check the pressure switch contacts. They should be open with no flow and close when the pump runs (consult service manual for specifics).
• Adjust or replace: If the switch has an adjustment screw, make only small adjustments following manufacturer guidelines. If the switch does not respond or is corroded, replace it with a compatible American Whirlpool pressure switch.

If your spa uses an electronic pressure sensor integrated into the control pack, diagnosis and replacement should be performed by a qualified technician.