We have a Leisure Bay hot tub that we purchased new approximately five years ago. The gfci breaker was replaced about one year ago due to not being able to be re-set. Recently, while in the tub, with everything running fine, the breaker trips. This is after any time from thity seconds to ten minutes or even half an hour. Sometimes the breaker can be re-set right away and will work for another ten or fifteen minutes before it trips again. Other times it will never trip at all, even after being in the tub for as much as an hour. Most recently I opened up the access panel and found a loose ground wire going to the air pump( i belive thats what it is). I tightened the wire and everything worked fine for a few days. The tub never trips the breaker while it is not running, only with both of the motors going. Occasionally it trips with the air pump off and the motors running. Never while it is un-occupied and maintaining temperature. The tub has a canister style heater assembly. After reading other posts I understand that heater corrosion could cause problems. Where is this corrosion likely and how do I identify this problem? Other problems seem less likely to me, but I'm just about at my wit's end trying to figure this one out. HELP!

In this scenario I would look into checking the blower motor, if you had a loose ground wire and it started shorting it is a possible cause of the GFCI tripping. Are you sure that it sometimes trips without the blower running? Check the Amp draw on the entire system while it is running, see if it pulls over 45 amps, that would be a little to close to where a 50 amp breaker would trip and may be able to be corrected by switching the spa into the 30 amp mode so that the heater cannot be activated while you are in the spa. Heater corrosion is not something that you can see without removing the control pak from the spa, you can disconnect the heater and check the element with an OHM meter, it should read anywhere between 9 and 12 MegaOhms if the element is ok, also check it for any type of continuity to ground, if it has any then the element is definetely bad and needs to be replaced immediately. Most Leisure bay spas use a vertical heater that the element cannot be swapped out in and therefore you would be required to replace the whole tube.