Spa trips the GFCI breaker immediately or within a few seconds of turning it on.

Safety first: Do not repeatedly reset a tripping GFCI; this indicates a potentially dangerous fault.

• Visual inspection: With power OFF, open the equipment bay and look for obvious signs of water leaks, burned components, or melted wiring.
• Isolate components: Disconnect one major component at a time (heater, Pump 1, Pump 2, ozonator, blower) from the control board, then try resetting the GFCI. When the breaker stops tripping, the last disconnected component is likely the culprit.
• Check heater first: The heater is a common cause. Disconnect heater leads from the board and test. If the spa powers up without tripping, the heater is likely shorted to ground.
• Inspect pumps: If disconnecting a pump stops the trip, the pump motor may be waterlogged or internally shorted and should be replaced.

Once the faulty component is identified, replace it with a Marquis-compatible part. If the breaker still trips with all loads disconnected, the control board or wiring may be at fault and requires professional diagnosis.