Understanding Sundance® Spas 780™ & 680™ Series Troubleshooting & Error Codes

Sundance® Spas 780™ & 680™ Series Troubleshooting & Error Codes

Whether you own a 780™ Series (Hamilton, Chelsee, Certa, Montclair) or a 680™ Series (Peyton, Edison, McKinley, Ramona), your spa uses an intelligent diagnostic system to keep your water safe and clean. If your control panel is flashing a code, use this guide to identify the fix.

Own an 880 Series Spa?
If you have an Aspen, Maxxus, Optima, or Cameo model, please see our Sundance 880 Series Troubleshooting Guide.

Common Sundance 780 & 680 Status Codes

Unlike the 880 series with its external cabinet light, 780 and 680 models rely on the LCD display to communicate status and maintenance needs.

Code What It Means Action Required
FLO / FL1 Flow Switch Error: The system detects no water movement. Check water level. Clean your filters immediately. If the error persists after cleaning, the flow switch may need replacement.
OH Overheat Protection: Water temp has reached 112°F (44°C). DO NOT ENTER WATER. The heater will deactivate. Remove the cover and let the water cool down. Reset the breaker if necessary.
Sn1 High-Limit Sensor: Safety sensor is open or shorted. The heater is disabled. This hardware fault typically requires a replacement High-Limit sensor.
Sn2 Temperature Sensor: Main thermostat sensor is faulty. The spa will not heat. Check the sensor connection to the board or replace the sensor.
ICE Freeze Protection: Water is below 55°F (13°C). No action needed. The pumps will run until the water reaches a safe temperature to prevent pipe damage.
blb / BLB CLEARRAY® Bulb Replacement: Timer has expired. Replace the UV bulb to maintain water sanitization and reset the timer on your control panel.

What to do if your Display is Flashing?

On many 780 and 680 models, a flashing temperature display or a flashing "Cooler" icon indicates a flow issue. Before calling a technician, try these three steps:

  1. Turn off the power: Shut off the GFCI breaker for 30 seconds to reset the logic board.
  2. Remove the Filter: Sometimes a "clean-looking" filter is actually clogged with oils. Run the spa without the filter for a few minutes; if the code clears, you need a new Sundance filter.
  3. Check for Air Locks: If you just refilled the tub, air might be trapped in the pump. Briefly loosen the pump union to let the air hiss out (burping the pump).

Need Sundance Spas Replacement Parts?

From MicroClean® filters to temperature sensors and CLEARRAY® bulbs, we have the genuine parts you need for your 780 or 680 series spa.

Shop Sundance Spas Parts at SpaStore.com
Feb 20th 2026 SpaStore.com

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