There’s nothing quite like slipping into your spa after a long day—until your control panel flashes an unfamiliar message and your hot tub shuts off.
Before you panic, take a breath. Most hot tub error codes are simply your system’s way of letting you know something’s off, and often something easy to fix.
This hot tub troubleshooting guide from Cal Spas of Minnesota walks you through the most common hot tub codes, what they mean, and when it’s time to call in a professional. Whether you’re seeing an SL code, DR code, or EC code, understanding your spa’s error codes will help you get back to relaxing faster.
Understanding Hot Tub Error Codes
Your spa’s control panel acts like a dashboard for your hot tub. When it detects an issue such as a pressure switch malfunction, low water flow, or temperature sensor error, it displays an error code to prevent potential damage.
Every brand and model has slightly different codes, so checking your owner’s manual is always a good first step. But some codes are universal, and once you know what they mean, troubleshooting becomes much easier.
Common Hot Tub Error Codes (& What They Mean)
Below is a general guide to some of the most common hot tub error codes and what you can do to resolve them.
Pro tip: Always start with the basics. A low water level or dirty filter is behind many hot tub errors.
Step-by-Step Hot Tub Troubleshooting Guide
When your spa flashes an error message, use this quick process to narrow down the cause:
- Read the exact code on your control panel.
Write it down before you reset anything. - Check your water level.
Make sure the water is above the jets but below the headrests. Too little water can cause flow problems or trigger DR codes. - Inspect your filter.
A clogged or dirty filter can restrict flow and cause a FLO error code. Remove and rinse it with a garden hose or swap it for a spare. - Reset your GFCI breaker.
If your spa is shut off completely, a tripped GFCI breaker could be the culprit. Reset it and see if the control panel lights back up. - Check for airlocks.
After draining or refilling, air can get trapped in the plumbing, causing a flow error. Open the bleeder valve or loosen a union fitting to release trapped air. - Verify temperature sensors.
If you see Sn, OH, or HL, your temperature sensors might be giving false readings. Inspect for corrosion or loose wires. - Review your spa mode.
If you’re getting an EC code on your hot tub, it’s likely in Economy Mode. This setting only heats during filtration cycles, so your tub may feel cooler than expected. Switch back to Standard Mode for steady warmth.
When to Call a Technician
Even the best hot tubs occasionally need a little expert attention.
Contact Cal Spas of Minnesota for service if:
- You’ve checked all the basics (water level, filters, sensors) and the error persists
- You suspect electrical or heater element failure
- You see recurring SL, SnS, or DR codes after multiple resets
- You hear unusual noises or your pump won’t turn on
- Your spa is shut down and won’t power back on
Our certified technicians can quickly diagnose and fix tub error codes so you can get back to soaking without worry.
Pro Tips to Prevent Future Hot Tub Errors
- Keep your filters clean: A clean filter keeps water flowing properly and prevents flow errors.
- Maintain your water balance: Proper pH and alkalinity protect your heater and sensors.
- Inspect your cover regularly: A snug, insulated hot tub cover maintains energy efficiency and protects against debris.
- Use your troubleshooting resources: Visit our Troubleshooting Resources Hub for more step-by-step fixes.
- Watch and learn: Prefer a video walkthrough?
→ Here are the 5 hot tub how-to videos you should be watching
FAQs: Hot Tub Error Codes & Troubleshooting
What are common hot tub error codes?
The most frequent codes are FLO (flow issue), OH (overheating), Sn (sensor issue), DR (dry heater), and EC (economy mode). Most relate to water flow or temperature regulation.
Why does my hot tub keep saying “error”?
Repeated errors usually point to an underlying issue, and often a dirty filter, low water level, or malfunctioning sensor. Persistent errors after basic troubleshooting should be checked by a technician.
How do I diagnose my hot tub problems?
Start with your control panel code, then check water flow, filters, sensors, and breaker. The owner’s manual or our Cal Spas professionals can help identify the cause.
How do you fix an E02 error on a hot tub?
The E02 error often means a flow problem caused by airlocks or blocked filters. Refill water, bleed air, and clean the filter to restore normal function.
What does F2, F4, F6, or F8 mean on a hot tub?
These typically refer to pump cycle settings (frequency of filtration cycles). They aren’t errors, but rather timer indicators.
What does E03 (or E02) mean on a hot tub?
These codes often indicate a low-flow or sensor error. Check filters and ensure water is circulating properly.
How to reset a hot tub?
Turn off power at the breaker, wait 30 seconds, then turn it back on. If your hot tub still shows an error code, the issue may require service.
Keep Your Hot Tub Running Smoothly Year-Round
A little regular maintenance goes a long way in keeping your Cal Spas hot tub performing beautifully, especially through Minnesota’s seasonal shifts.
If you’re unsure about an error code, need help troubleshooting, or want to book professional maintenance, our team is ready to assist.
From spa covers to replacement filters, Cal Spas of Minnesota has everything you need to extend the life of your spa and enjoy the perfect soak every time.