Gecko Troubleshooting Guide (S-Class Systems)
Fault code diagnosis and component testing for Gecko S-Class spa control systems including MSPA-MP.
Common Control Panel Problems This Guide Covers
A technician should open this when diagnosing error codes, sensor faults, or component failures on any Gecko S-Class spa control system, including MSPA-MP boards..
What it helps you resolve
- Spa display showing SN or SN1/SN2/SN3 error
- Display showing OH , water temperature exceeded limit
- Display showing OHH , high limit sensor tripped
- Display showing FL1 or FL2 , flow switch or pressure switch fault
- Spa not heating despite correct thermostat setting
- ICE error appearing in cold-weather operation
- COOL displayed when spa is not overheating
- Pump running but no heat
When not to use
This guide covers S-Class systems only. For Y-Series or in.XE systems, use the corresponding Gecko troubleshooting guide.
Fault codes covered
Quick diagnosis
SN codes indicate sensor faults , measure resistance across the sensor leads with the board unpowered. OH/OHH indicate overheating; check flow rate and heat exchanger scaling before replacing sensors. FL1/FL2 indicate flow switch issues , inspect the flow switch and pressure switch before suspecting the board.
Still seeing issues with your Gecko Troubleshooting Guide (S-Class Systems)?
Our certified technicians know every fault code in this document, including SN, SN1, SN2, and can diagnose your Gecko control panel in person across the Oak Island area.
Request ServiceGecko Control Panel FAQs
What does SN mean on a Gecko S-Class spa?
SN (or SN1, SN2, SN3) indicates a temperature sensor fault. The control system has detected an open or shorted sensor circuit. Disconnect the sensor leads and measure resistance with a multimeter , a good sensor reads within the specified range in this guide. Replace the sensor if it reads open or shorted.
What does OH mean on a Gecko S-Class system?
OH means the water temperature has reached or exceeded the high-limit threshold (typically 112°F/44°C). Do not enter the spa. Allow the water to cool, then investigate the cause: check for adequate flow, a dirty filter, or a stuck circulation pump before attributing the fault to the temperature sensor.
What does OHH mean on a Gecko S-Class system?
OHH indicates the high-limit sensor (separate from the thermostat sensor) has tripped. This is distinct from OH and typically indicates a localized overheat at the heater tube. Check for restricted flow through the heater and verify the high-limit sensor is properly seated in its well.
What does FL1 or FL2 mean on a Gecko S-Class spa?
FL1 and FL2 indicate flow faults. FL1 typically indicates the flow switch has not closed, meaning insufficient water flow through the heater. FL2 indicates the flow switch opened during operation. Check that the main pump is running, the filter is clean, and the flow switch is not stuck open before replacing components.
What does ICE mean on a Gecko spa controller?
ICE is a freeze protection warning. The control system has detected a water temperature low enough to risk freezing and has activated the circulation pump to protect the plumbing. This is normal behavior in cold weather and does not require service unless the spa fails to heat after warming conditions return.
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Qualified personnel only. Opening electrical panels, control boards, or equipment enclosures involves dangerous voltages and should only be performed by licensed pool or electrical technicians. Unauthorized service may void your manufacturer warranty. If unsure, contact a qualified professional.