It’s finally the weekend, and you’re ready to sit back and relax in your bubbling, steamy hot tub with your friends and family. You put down your fresh, fluffy towel and remove your hot tub cover…only to find the water is ice cold.

Or maybe you turn on the jets, but nothing happens. Or the jets work just fine, but the water is ridiculously hot.

Whatever inconvenience you experience, one thing is for certain — this is not how you were planning on spending your evening. But before you panic, take a look at the troubleshooting guide below and see if it’s something you can DIY first. There are a variety of common hot tub issues with simple solutions that will get you back into your bubbly oasis as soon as possible.

Don’t Panic! Simple Solutions May Help.

Common Error Codes and Display Messages

These are the error codes and display messages that a Sundance Spa may display, along with what they mean and what action should be taken.


This stands for “Overheat” and the tub shuts down because one of the sensors detected that the water in the hot tub is 112°F (44°C), which isn’t safe. The circulation pump will stop functioning to reduce frictional heating when water temp reaches 2°F (1°C) more than the set temperature.

Action Required: Don’t enter the water. Instead take off the hot tub cover to allow the water to cool down. Shut the power down to the hot tub. If the problem continues, contact the dealer or service technician.


If the spa water is more than 19.4°F (-7°C) colder than temperature set points, the Jets pump #1 and heater will automatically activate to provide freeze protection. The system will stay in this mode until water temps rise to 59°F (15°C) below the set temperature.

Action Required: None


Standing for Flow Switch, this means it’s malfunctioning or the flow of water is being inhibited. The heater is deactivated and filter/circulation may be deactivated, also.

Action Required: Check for clogged filter and proper water levels in the hot tub. This message might also appear after the hot tub has been drained and refilled, and the pump has not regained its prime.


Circuit board temperature has exceeded acceptable limit. The message will go away once the board temperature cools down to below acceptable limits.

Action Required: If you continue to see this message, provide shade for the equipment part of the hot tub.


A potential freeze condition has been detected by the system. The jet pumps operates until the hot tub is out of danger zone.

Action Required: None, but note that this message may appear when hot tub is filled for the first time because tap water is usually very cold.


Power Failure. The low voltage is the result of power fluctuating in the secondary power line.

Action Required: Try to reset the spa power. If power levels return to normal, the PF error will reset itself.


Communication between the hot tub’s control panel and circuit board and/or remote control panel is faulty.

Action Required: Contact dealer or qualified service technician.

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This is the “watchdog” message when the water temperature is above acceptable limits. Do not enter the water.

Action Required: Take off the cover to speed up the cooling down. A problem has been detected that could do damage to your hot tub. Contact dealer or qualified service technician.


Open Sensor or Sensor 1, this means the high-limit sensor is malfunctioning.

Action Required: Contact dealer or qualified service technician.


The main temperature sensor is not functional.

Action Required: Contact dealer or qualified service technician.


This means that the flow switch is non-functional. The system is disabled, and system startup has shorted or has a closed flow switch in this situation.

Action Required: Contact dealer or qualified service technician.


Also means that the flow switch is non-functional.

Action Required: Contact dealer or qualified service technician.


Indicates that the UV bulb needs to be replaced. The message will flash between “bLb” and the water temperature.

Action Required: Purchase a new UV bulb from Emerald Leisure Source and then reset the countdown timer.

Thinking About a Hot Tub for Your Home?

Emerald Leisure Source, right in Grand Rapids, Michigan, is your one-stop shop for brand new Sundance Spas, covers, chemicals, and everything you need to make your hot tubbing experience the best it can be. Stop in and talk with our expert staff today!