Display shows dr or DR, heater will not run, and spa may shut down after attempting to heat.

Safety: Turn off power at the GFCI. Running a dry heater can permanently damage it.

• Check water level: Ensure the spa is filled to the recommended level, typically above all jets and suction fittings.
• Bleed air from heater: Loosen the union on the heater inlet or outlet slightly until air escapes and water begins to seep, then retighten. This removes trapped air.
• Clean or remove filter: Remove the Microfilter cartridge and rinse thoroughly. Temporarily run the spa without the filter to see if the dr code clears (do not leave it this way long-term).
• Verify circulation pump: With power restored, confirm that water is visibly moving in the footwell or through the heater return. If there is no movement, the circulation pump may have failed.

If dr persists after ensuring proper water level, bleeding air, and cleaning the filter, the heater or circulation pump may be damaged and should be evaluated by a technician.