1. Have a Caldera Utopia Niagara model spa, 2003. S/N N1B1E1008

2. Main Power Input are two circuits, a 20 amp and a 30 amp fed by two GFCI's (per manufacturers instructions) and the circuits land on the main control board in the spa.

3. Topside control; Electronic type.

The tub had been working fine since installation. Recently, the 30 amp GFCI has tripped and attempts to reset it simply result in an immediate trip upon breaker reclose. Replacement of the GFCI with a new unit produces the same result.

Ringing out the circuit shows the trip occurs only when the 30 amp "red" circuit is energized with the ground (green) carried to the panel and connected (again, per manufacturers instructions). In other words, if the green ground is disconnected from the control panel ground lug, the spa operates normally. As soon as the feedign circuit green ground lead contacts the control panel ground lug, the GFCI trips.

Checking the circuits, there is no cable-feed short between neutral (white) and ground (green). Given the fact the problem has only recently surfaced and that nothing has changed in the feeding circuit, we believe the problem is on the main circuit board where there might be leakage current flowing from a failed board component to ground.

OUR QUESTION...
Has anyone experienced this problem with the Utopia Niagara model? Please comment.

Is the spa operational with only (1) breaker on? Which one?

It's more likely that a component using the 30 amp breaker for power has developed a ground fault. Although the circuit board is a possibility...I'd disconnect whatever component uses the 30 amp line, and see if you can isolate a bad part. If it still trips with all the equipment that relies on the 30 amp breaker disconnected (including the heater?), it may well be the circuit board. If it uses a seperate transformer, that's a possibility as well.

Good luck!