Circulation pump is not running; water at heater return is still and spa may not heat.

Safety first: Turn off power before working on the pump or plumbing.

• Check for air lock: Loosen the unions on the circulation pump to release trapped air until water flows, then retighten.
• Verify power to pump (advanced): With power on and spa calling for heat, a technician can measure voltage at the circulation pump terminals. If voltage is present but the pump does not run, the pump is likely failed.
• Replace circulation pump: Drain water below pump level, disconnect unions and wiring, and install a new Dynasty-compatible circulation pump. Refill, bleed air, and test.
• Control board check: If no voltage is present at the pump when it should run, the control pack may have a failed relay and require repair or replacement.