Gecko Hot Tub Error Codes Explained
Gecko control systems are used in many different hot tub brands, so seeing a Gecko error code does not always mean you own a “Gecko spa.” It usually means your hot tub uses a Gecko control pack, circuit board, or topside control panel.
This guide explains common Gecko hot tub error codes, what they usually mean, and what you should check first before replacing parts or calling a technician.
Different Gecko systems may display codes differently. For example, one spa may show HL, while another may show OH, or a longer message on the topside display. The meaning is often similar, but the exact wording depends on the control system and topside panel.
Not Sure If You Have a Gecko System?
To identify a Gecko control system, start by looking inside the spa equipment area for the main spa pack, which is usually a gray or black control box connected to the heater, pumps, keypad, and incoming power. Most Gecko systems have a product label on the outside of the control box that lists the model family, such as in.xe, in.ye, in.yt, in.yj, in.xm, or in.xm2, along with an ID number and electrical rating. The topside keypad can also provide clues, especially if it uses Gecko model names like in.k200, in.k500, in.k800, or in.k1000, but the keypad alone does not always identify the actual control pack. For the most accurate identification, compare the label on the spa pack with the wiring diagram inside the control-box cover and the model number printed on the product sticker. Gecko notes that product labels may include version details such as V2 or V3 and a 13-digit ID number, while Gecko techbooks also recommend checking the wiring diagram inside the enclosure cover for pack-specific information.
Some spa brands may use Gecko controls on certain models and Balboa, proprietary, or other systems on others.
Find Your Gecko Error Code Fast
On Desktop
Press:
- CTRL + F on Windows
- CMD + F on Mac
- Then type your code
On Mobile
Use your browser’s Find in Page feature.
On Android Chrome:
- Tap the three-dot menu
- Tap Find in page
- Type your error code
On iPhone Safari:
- Tap the share button
- Tap Find on Page
- Type your error code
Quick Gecko Error Code Chart
Flow Errors
Helpful Articles: Hot Tub Flow Issues?, Hot Tub’s Pump Isn’t Starting?
| Code / Message | Basic Meaning |
|---|---|
| FLO / FLO – L01 / FLO – L02 | Insufficient water flow detected through the heater |
| NO FLO | Persistent no-flow condition |
| RH – NF | No-flow condition detected by the in.therm heater. |
| CFLO | No-flow condition in the in.clear system. |
| FLC | Flow switch closed when it should not be closed |
Heater Errors
Helpful Articles: Hot Tub High Limit, Hot Tub Isn’t Heating,
| Code / Message | Basic Meaning |
|---|---|
| HL | High-limit protection activated. Water at the heater has reached an unsafe temperature |
| OH / SP – OH | Overheat warning. Water too hot |
| RH – HR | Hardware error detected in the in.therm heater |
| RH – NH | Heater is trying to heat but does not detect a temperature increase |
| RH – HL | High-limit hardware circuit tripped |
Sensor Errors
| Code / Message | Basic Meaning |
|---|---|
| PR / PRR | Problem with the regulation/temperature probe |
| RH – PR | Problem with the regulation probe |
| PrH / Prh | High limit sensor fault |
Status Messages
| Code / Message | Basic Meaning |
| Loc | Keypad locked |
| LocP | Partial keypad lock |
| LocF | Full keypad lock |
| ULOC | Keypad unlocked |
| BOO | Boost mode enabled |
| CLE | Clean filter reminder |
| OFF | Standby Mode |
System Errors
| Code / Message | Basic Meaning |
|---|---|
| Hr | Internal hardware error. On some systems, this can also refer to a thermal fuse error |
| HR | Hardware/relay error, often “relay stuck” on color keypads |
| AOH | Internal pack temperature is too high / temperature inside the spa skirt is too high |
| UPL | No valid low-level configuration/software in the spa pack. Needs valid in.stik programming |
| SP – IN / SP in | Input voltage issue / voltage too low |
| SC ER | Error detected during learning mode |
| ER1 | Swim spa configuration error: slave unit missing |
| FR – ER / Fr – Er | Input frequency, 50/60 Hz, is out of range |
| F1 / SP – F1 | Fuse 1 blown |
| F2 / SP – F2 | Fuse 2 blown |
| F3 / SP – F3 | Fuse 3 blown |
| SP – OT | Spa pack/internal hardware temperature too high |
| RH – NC | Communication problem between in.xm2 and in.therm |
| RH – ID | in.xm2 and in.therm are incompatible / model mismatch |
| Comm / Co error | Communication/cable issue between in.clear and the spa pack |
| Supp | Connect power cord to 240V source |
| Err | in.clear diagnostic error. Can be tied to low BromiCharge warning that does not clear, calcification, air bubbles/low flow, or internal pressure switch issue. |
| HP1 – 99 | Heat pump service/error code 1–99. Contact dealer/service technician |
Before Troubleshooting Any Gecko Code
Before replacing parts, check the simple things first:
- Make sure the water level is high enough.
- Remove and rinse the filter.
- Check that all slice valves are fully open.
- Look for air locks after refilling the spa.
- Confirm the pump is moving water.
- Restart the spa only after correcting the obvious issue.
- Never bypass safety devices to “test” the spa.
Many Gecko error codes are caused by poor water flow, dirty filters, low water level, air locks, or circulation problems. Start there before assuming the circuit board, heater, or sensors are bad.
When to Call a Hot Tub Technician
Call a technician if:
- The same error code keeps coming back
- The spa will not heat
- The breaker trips
- The pump is not moving water
- The spa shows an overheat warning
- You see signs of melted wiring or burned components
- The topside shows no communication
- You are dealing with GFCI, circuit board, or sensor testing
Many simple flow problems can be checked by a homeowner, but electrical testing and control board diagnosis should be handled by someone qualified.
Gecko error codes are easier to understand once you group them by problem type. Many of the most common codes are related to water flow, heater protection, overheating, or temperature sensors.
Start with the simple checks first: water level, filter condition, pump operation, air locks, and open valves. If the code keeps returning after those checks, the spa may need professional diagnosis.
As this guide grows, more Gecko codes and model-specific notes will be added.
Written by: Dan Harvickson (Founder of Last Mountain Tech), Pool and Spa Technician.