Control panel displays “dr” and spa will not heat; circulation pump may run briefly then stop.

Safety first: Turn off power at the GFCI breaker before opening any equipment compartment or touching internal components.

• Check water level: Ensure the water level is above all filters and suction fittings. Top off the spa if needed.
• Bleed air from circulation pump: After refilling, loosen the union on the SilentFlo 5000/5002 circulation pump slightly to let trapped air escape, then retighten. Restore power and see if the error clears.
• Clean or remove filters: Remove all Tri-X or standard cartridge filters and run the spa with no filters for 10–15 minutes. If the code clears, thoroughly clean or replace the filters.
• Inspect pressure/flow switch: Locate the heater pressure switch or flow switch on the heater plumbing. Check for loose wires and obvious damage. If the spa runs normally with good flow but still shows “dr”, the switch may need replacement.

If the error persists after confirming water level, bleeding air, and cleaning filters, contact a qualified Hot Spring technician to test the circulation system and safety sensors.