Jacuzzi / Sundance · Jacuzzi J-300 / J-400 and similar Sundance panelsStop using the tub

-- on a Jacuzzi / Sundance hot tub: watchdog shutdown

The system has detected a problem that could damage the spa or its parts and has shut the spa down. Do not use the tub. Contact a dealer or technician.

Also shown as: - -, ----, watchdog

Most likely causes

  1. 1Water temperature or heater reading far out of rangecommon
  2. 2Failed sensorcommon
  3. 3Circuit board faultcommon

What to try, in order

  1. Stay out of the water.
  2. Turn the tub off at the breaker for a minute, then back on, and see if it restarts normally.
  3. Check the water temperature with a thermometer.
  4. If dashes return, leave the tub off and call for service.

-- questions

Do dashes always mean a watchdog fault?

No. On Balboa-controlled tubs, dashes just mean the temperature is not known yet. On Jacuzzi and Sundance panels that list a watchdog code, steady dashes with the spa shut down mean a fault.

Is it safe to reset and keep using it?

One reset is reasonable. If the dashes return, stop and have it checked.

Related codes

Balboa -- · Temperature not yet knownJacuzzi / Sundance COOL · Water 20°F below setJacuzzi / Sundance FL1 · No flow detectedJacuzzi / Sundance FL2 · Flow switch stuck closedJacuzzi / Sundance FLO · Flow switch problemJacuzzi / Sundance HOLD · Panel buttons locked outJacuzzi / Sundance ICE · Freeze protection activeJacuzzi / Sundance OH · Overheat protection

General guidance. Follow your manufacturer's instructions; anything inside the control box is work for a licensed professional. Updated October 5, 2026.