How to read a pool or hot tub error code
A code is the control board telling you which safety check failed. Most codes on hot tubs and heaters come down to water flow or temperature: the board turns the heater off to protect it, then shows a short code. The same letters can mean different things on different brands, so always look up the code for your exact brand and model.
- Write the code down exactly. Note any letters, numbers and whether it flashes or alternates with the temperature.
- Find your model. The model is on the control box, the spa pack label or the heater’s rating plate.
- Look it up here. Pick the type, then the brand and model, then type the code.
- Do the checks in order. Start with the easy ones: water level, filter, valves and power.
- Reset the way the manual says. Some codes clear by themselves, some need a button, and some need the power turned off and on.
What the most common codes have in common
| What it means | Examples | Check first |
|---|---|---|
| No or low water flow | FLO (Gecko), HFL and LF (Balboa), E90 (Intex), E02 (Bestway) | Water level, a clean filter, open valves, air in the lines |
| Water too hot | OH (Gecko), OHS (Balboa), E95 (Intex), E04 (Bestway) | Cover off, let it cool, shorten filter cycles |
| Water too cold | E94 (Intex), E03 (Bestway) | Warm the water before you start the heater |
| Heater ignition or pressure fault | IF and LO (Hayward), ERR IGN and ERR PS (Pentair) | Gas supply, flow, a dirty filter |
Stop. If a code keeps coming back after the checks, if a breaker or GFCI trips, or if you smell gas near a heater, turn the power off at the breaker and call a pro. Do not open the control box or a gas valve yourself.
Common questions
How do I reset a hot tub error code?
Fix the cause first, then follow your manual: many codes clear on their own once flow or temperature is back in range, others need a button press or turning the power off and on. Resetting without fixing the cause brings the code back.
What does FLO mean on a hot tub?
On Gecko spa packs, FLO means the system sees no water flow while the main pump runs. Check the water level, clean or remove the filter to test, open all valves and bleed trapped air.
Why does my inflatable hot tub show an error after I fill it?
Cold fill water and trapped air are the usual causes. Intex E94 and Bestway E03 mean the water is too cold, and flow codes often clear once air is purged and the filter is seated.
Where does this code list come from?
Every code comes from the maker’s own owner’s manual or troubleshooting guide, and each result links to that document. Codes we could not find in an official document are left out.