How to Resolve Error Codes on Hot Tub Displays

How to Resolve Error Codes on Hot Tub Displays

Seeing a strange code on your hot tub panel can feel like a dead end. But most hot tub error codes are easy to decode with a little knowledge. These codes are your spa’s way of telling you something isn’t right. Once you know what the code means, fixing the issue often takes just a few minutes.

Why Hot Tubs Display Error Codes

Hot tubs are equipped with control systems that monitor things like temperature, water flow, and sensor performance. When something goes outside of the safe operating range, the system triggers an error code.

These codes protect both the spa and the user from unsafe conditions. Fixing them quickly ensures your hot tub runs efficiently and avoids long-term damage.

Safety First Before Troubleshooting

Before you touch anything:

• Turn off power at the breaker
• Allow the system to cool if it overheated
• Never try to override safety sensors
• Refer to your hot tub’s owner manual for model-specific instructions

Also, inspect the surrounding area for signs of moisture, unusual smells, or noise. These can give you clues about electrical or mechanical issues before you even start diagnosing.

Common Hot Tub Error Codes and Fixes

Here are the most frequent error codes you’ll see and what they usually mean.

1. FL, FLO, or FLC – Flow Error

This indicates a problem with water flow. The heater may shut off to prevent damage.

Possible causes:

• Dirty or clogged filter
• Low water level
• Airlock in plumbing
• Faulty or weak circulation pump

How to fix:

1. Turn off the hot tub
2. Remove and clean the filter thoroughly
3. Check water level and refill if low
4. Open an air bleeder valve or loosen a union to release trapped air
5. Turn the system back on and monitor circulation

If the error returns, inspect the pump impeller for blockages or replace the filter entirely if it’s over a year old.

2. OH or OHH – Overheat

This means the spa water is too hot, usually over 108°F.

Possible causes:

• Pump running continuously due to another fault
• High ambient temperatures
• Malfunctioning temperature sensor

How to fix:

1. Shut off the spa and remove the cover to let heat escape
2. Wait until water temperature drops to a safe range
3. Inspect the circulation cycle for abnormalities
4. Test the sensor resistance or replace it if the issue persists

Never ignore this code. Prolonged overheating can damage plumbing, jets, and internal components.

3. SN, SN1, SN2 – Sensor Error

Sensor errors usually involve temperature or flow sensors giving incorrect or no readings.

Possible causes:

• Sensor wires disconnected or frayed
• Corroded terminals
• Bad sensor placement or faulty sensor itself

How to fix:

1. Turn off power to the spa
2. Open the access panel and locate the sensor wiring
3. Check all connections for corrosion, moisture, or loose plugs
4. Test the sensor’s resistance with a multimeter (check your manual for correct values)
5. Replace the sensor if readings are off

4. DR or DRY – Heater Dry Error

This means the heater is running without enough water, which could cause internal damage.

Possible causes:

• Low water in the tub
• Blocked intake or suction line
• Airlock in plumbing lines

How to fix:

1. Confirm the water level is correct
2. Check for any suction blockages or debris near filters
3. Bleed air from the system
4. Reboot the spa to reset the code

Also inspect the pressure switch, which may falsely trigger this code if it’s worn or misaligned.

5. LO or COOL – Low Temperature Warning

This means the water temperature has fallen too low, typically under 50°F.

Possible causes:

• Cold outdoor conditions
• Spa left off for too long
• Faulty heater or thermostat

How to fix:

1. Turn the spa to standard heating mode
2. Use an insulated spa cover to retain heat
3. Inspect the heater for scale or corrosion
4. Verify voltage and relay functions on the circuit board

Low temperature warnings are critical in winter. Prolonged exposure can freeze plumbing and crack pipes.

6. EC or ECON – Economy Mode

This is not a fault. It’s a power-saving mode where the heater only activates during filter cycles.

How to adjust settings:

1. Access the main menu or mode settings
2. Switch from economy to standard or ready mode
3. Consult your owner’s manual for steps specific to your model

Running in economy mode during freezing temperatures can leave the spa vulnerable to low heat errors.

How to Reset Your Hot Tub After Fixing an Error

Resetting your spa helps clear out the error code and start fresh.

1. Turn off the spa using the control panel or breaker
2. Wait at least 30 seconds to allow a full shutdown
3. Turn the power back on and monitor the startup sequence
4. Test basic operations: jets, lights, heater, and temperature readings

If the error persists, it could point to deeper problems like damaged control boards or wiring shorts.

Tips for Preventing Future Errors

• Clean filters weekly: Dirty filters are the number one cause of flow errors
• Keep water balanced: Prevent scale on sensors and reduce heater stress
• Check water level before every use: Prevent low flow and dry heat conditions
• Use a thermal cover: Especially in cold climates, to retain heat
• Replace sensors every few years: Prevent corrosion and electrical drift

Regular maintenance prevents most errors before they start.

When to Call a Professional

Some issues go beyond DIY and require a technician.

Call for help if:

• You hear unusual noises like humming or grinding from the pump
• The circuit board shows signs of burn marks or swelling
• You see bubbles or water near electrical parts
• The display remains blank even after power cycles

A qualified spa technician can test voltage, diagnose circuit faults, and replace hardware safely.

Learning how to read and fix hot tub error codes puts you back in control of your spa. With the right approach, many issues can be solved in minutes, not hours. Keep a cheat sheet of your spa’s most common codes handy so you can respond quickly next time the panel flashes a warning.