Blog

Sundance Circuit Board Guide (6600-726 vs. 6600-720) The "Hidden" Difference: Series 3 vs. Series 5 The Sundance 6600-726 and Sundance 6600-720 boards look identical, but they use different software logic. Installing the wrong one can prevent your heater or circulation pump from running. Check your EPROM Chip: Look at the small white sticker on the main processor of your old board. Chip starts with a "3": Use the 6600-726. This supports spas with a circulation pump (like the Certa or Chelsee). …

Is Your FLO Error Flashing or Solid? A "FLO" error is the most common message on a Sundance control panel. To fix it, you first need to identify which type you have: Flashing FLO (or FL1): This means the system wants to see water flow but can’t. This is usually caused by a dirty filter, an air lock after a drain-and-fill, or a Flow Switch stuck in the "open" position. Solid FLO (or FL2): This means the system thinks there is flow even when the pumps are off. This is almost always a sign t …

Spa Troubleshooting Guide Hot tub circuit board problems can cause a wide range of confusing symptoms—from no heat and error codes to pumps turning on by themselves or GFCI breakers tripping. This guide explains the most common circuit board–related issues, what causes them, and how to safely diagnose the problem before replacing parts. The goal is to help you understand what your spa is doing and why, so you can make the right repair decision with confidence. Click a question below …

Click a question below to jump to the answer: Why won’t my Sundance spa heat? What do Sundance error codes mean? Why does my GFCI trip? Why does my pump run on its own? Why is my display acting strangely? Why don’t the spa buttons respond? Why are power connections burned or melted? Helpful tips most Sundance owners aren’t told Why won’t my Sundance spa heat? Symptoms: Heat light on/off, no water heating, error codes like FLO or FL. Causes & Sundance Fixes: Pressu …

It is the nightmare scenario for every spa owner: the temperature is plummeting, the wind is howling, and you realize your hot tub’s circulation pump has stopped. Without moving water and the heat generated by the system, your spa’s internal plumbing becomes a ticking time bomb. When water freezes, it expands, and it will easily crack PVC pipes, manifolds, and pump housings, leading to thousands of dollars in repairs. If your pump is dead, you are in a race against time. You have a w …