Display shows dr or DR and heater shuts down; may be accompanied by low heat complaints

Safety: Turn OFF power at the GFCI breaker before working on the spa.

• Check water level: Ensure the spa is filled to the proper level. Top off if needed.
• Inspect suction fittings: Check that all skimmer baskets and suction covers are free of debris, leaves, or toys that could restrict flow.
• Bleed air from heater and pumps: Loosen the unions on the heater inlet and outlet and on the circulation and jet pumps until air escapes and water seeps out, then retighten.
• Verify pump operation: Restore power and run the pumps on high speed. Confirm strong flow from jets and any dedicated circulation outlets.
• Monitor for dr: If the dr code reappears, shut power OFF and repeat bleeding. Persistent dr may indicate a weak or failing circulation pump.
• Replace circulation pump if needed: If the circ pump is noisy, hot to the touch, or not moving water, replace it with an OEM Michael Phelps/ Master Spas-compatible circulation pump. This involves shutting power OFF, closing slice valves, disconnecting unions and wiring, swapping the pump, then reopening valves and bleeding air.