Troubleshooting "FL1" and "FL2" Water Flow Error Codes on Your Sundance® 980 Series Hot Tub

Owning a luxury spa like the flagship Sundance® Spas 980 Series brings resort-style hydrotherapy directly to your backyard. With sleek cabinetry, advanced SunSmart 2.0 WiFi touchscreens, and energy-efficient circulation pumps, these units are engineered for high performance during harsh Ontario winters.

However, if you check your control panel and spot an FL1 or FL2 error code flashing, your spa has halted its heating cycles to protect itself.

In freezing weather across Durham Region, York Region, the Kawarthas, and Muskoka, a flow error requires fast attention to prevent cold-water freeze-ups. Here is what FL1 and FL2 mean, how to troubleshoot them, and how to get your spa running safely.

What Do FL1 and FL2 Error Codes Mean?

Both codes relate to the flow switch inside the heating manifold, which measures whether water is moving across the heater element.

• FL1 Error: The control board detects that the flow switch is open when it should be closed. In short, the system is calling for heat or filtration, but it doesn't sense enough water moving through the circulation plumbing.
• FL2 Error: The control board detects that the flow switch is stuck closed when the circulation pump should be off. This usually points to a shorted flow switch microswitch or a relay issue on the circuit board.

When an FL1 code triggers, the system turns off the heater element to prevent dry-firing and melting internal components. If the water stops moving during sub-zero temperatures, stagnant water inside the plumbing lines can freeze quickly.

Step-by-Step FL1 Flow Error Troubleshooting

Before calling for field service, perform these preliminary checks:

1. Inspect and Clean Your MicroClean® Ultra Filter

The most common cause of an FL1 error on a 980 Series spa is a dirty or clogged filter.

• Turn off the power at the house GFCI breaker.
• Remove the filter cover and pull out the pleated filter and MicroClean® inner core.
• Rinse the pleated filter thoroughly or replace the disposable core if it is older than 6 to 9 months.
• Restore power without the filter installed for a brief 5-minute test. If the FL1 code vanishes, a clogged filter was the culprit.

2. Check Water Level

Ensure your water level sits near the middle of the skimmer opening or top jets. If water levels drop too low, air gets sucked into the suction lines, causing airlocks or low flow across the switch.

3. Bleed Potential Airlocks

If you recently refilled your tub, an air bubble might be trapped inside the circulation pump impeller housing. To clear it:

• Turn off the GFCI breaker.
• Loosen the upper bleed valve or pump union slightly until water escapes, then re-tighten.
• Restore power.

When to Call for Emergency Field Service

If your water level is correct, your filters are clean, and the FL1 or FL2 code persists, the issue involves internal hardware. Common technical causes include:

• A failed flow switch with worn physical micro-contacts.
• A seized circulation pump motor or damaged impeller.
• Blown fuse links or faulty relays on the primary circuit board.

During sub-zero weather, do not leave your spa unheated while waiting. If your water temperature drops continuously, explore our specialized Hot Tub Service & Repair Page to understand our repair capabilities, or contact our team immediately via our Emergency Hot Tub Repair Page to request priority dispatch across Uxbridge, Port Perry, Whitby, Oshawa, and Muskoka.

Explore full model lineups on our main Sundance® Spas Collection Page.