Display shows dY or DY; spa may not heat properly and may shut down heater quickly

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

• Verify water level and filters: Ensure the spa is filled to the correct level. Remove and thoroughly clean or replace the Bullfrog filter cartridges.
• Bleed circulation system: Loosen the union on the circulation pump and heater until water flows steadily, then retighten. This ensures the heater tube is completely flooded.
• Check for suction obstructions: Inspect the spa interior for blocked suction covers or debris that could restrict flow to the circulation pump.
• Observe circulation pump: Restore power and watch the circulation pump during a heat cycle. If it starts and stops frequently, or you see bursts of air at the return, the pump may be drawing air or failing.
• Inspect for leaks on suction side: With the pump running, look for small air bubbles entering the spa from the heater return. This can indicate a suction-side air leak at a union or fitting that needs tightening or resealing.

If dY persists after ensuring solid, continuous flow, the heater or control pack may be overly sensitive or damaged; professional evaluation is recommended.