Jacuzzi error codes
Updated October 2026
On a Jacuzzi hot tub, a code takes turns with the water temperature on the display, often with a scrolling message. Here’s what each one means on J-300 series tubs, and what to do.
Type your Jacuzzi code into the troubleshooter for the safe checks.
Look up a codeWhat Jacuzzi codes mean
| Code | What it means | What to do |
|---|---|---|
| COOL | The water is 11°C or more below the set temperature, usually after a refill. The tub is heating up. | No action needed. |
| ICE | Frost protection. The water is below about 13°C, so the pumps and heater run in turns until it reaches about 18°C. | No action needed. |
| FL--1 | Flow error open: a dirty filter, an air lock at the circulation pump, or a flow switch stuck open. The heater turns off. | Do the checks below. |
| FL--2 | Flow error closed: the flow switch is stuck closed. The heater turns off. | Needs an engineer. |
| FL--3 | Flow error toggle: the flow switch is switching on and off erratically. | Clean the filters and check the water level. If it comes back, call us. |
| SN--1 | The high-limit sensor isn’t working. | Needs an engineer. |
| SN--2 | The water temperature sensor isn’t working. The heater turns off. | Needs an engineer. |
| HOT | The water is getting too hot. After five minutes the display changes to T--OH. | Take the cover off and let it cool. |
| T--OH | The water has reached 44°C. | Don’t get in. Take the cover off and let it cool. Call us if it comes back. |
| H--OH | The high-limit sensor reads too hot. | Don’t get in. Call us. |
| -- -- -- -- | Watchdog: the safety software has found a problem and switched the tub off. | Don’t get in. Call us. |
These are the J-300 series codes. Other Jacuzzi ranges and older tubs can differ, so check your manual or our error code guide.
FL--1: what to check
- Switch off at the isolator.
- Check the water is above all the jets but below the lowest headrest. Top up if needed.
- Take the filters out and clean them.
- Switch back on. If the circulation pump isn’t running, switch off at the isolator and on again.
If FL--1 comes back, the usual causes are an air lock at the pump, a worn pump or a faulty flow switch. Those are jobs for an engineer.
Red lights flashing on and off on a Jacuzzi tub mean an overheat or Watchdog shutdown. Keep everyone out of the water.
Reminder messages
Some scrolling messages are timers, not faults. CHANGE FILTER, CHANGE WATER and CHANGE CLEARRAY BULB mean a reminder has run out. Do the job, then reset the timer from the panel menu.
Back up and running
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Jacuzzi code still showing?
Switch off at the isolator, then ring or WhatsApp us with the code and a photo of the panel.
If your tub is sunk into decking or the ground, or set against a wall, it helps to mention it when you book. If you’re not sure, a photo is fine.
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