VS500Z GFCI Tripping

[johnovision27]

Hey there folks.

I'm quite perplex with this issue and hope someone else can make sense of it. Board installed is a Balboa VS500z

Running out of a 2007 Hydrospa, without issue to this point, the heater went a few weeks ago causing the GFCI to trip. I verified this with no resistance through the heating element (opposed to the normal 13-14ohm)

I didn't have parts on hand and it was relatively inexpensive for a technician to come over and replaced the element. He did so without issue and everything seemed fine.

Last week the GFCI randomly tripped again. Tried troubleshooting the issue now that I had some spare time and it seemed to point back to the new heater but with a twist.

The heater was showing continuity and the proper resistance but the GFCI would trip when connected. With the heater disconnected for troubleshooting, the lower tandem relay wasn't passing voltage through it when the heater light was on, so I assumed it was toasted. Pulled the board, replaced the relay and the one above it for good measure and reinstalled everything. The new heating element still showed solid resistance and it wasn't in contact with the heater tube.

GFCI tripped again. 

I replaced the heater assembly (sensors and element) with a spare unit that I picked up for a good price, just for trouble shooting, and the tub fired back up.

Went through its internal tests successfully and then resumed normal operation for about 2 minutes and then tripped again with the same outcome. 

Everything else seems to run normally (circ pump, ozone, jet pump, light, and blower), GFCI stays powered with everything but the heater hooked up. Even the heater terminals are showing 240-250v when powered. In both cases the heater still showed good continuity and resistance.

Is it possible I've tested 2 bogus heaters or is something else at play here?  None of the solder joints on the board looked burnt or "cold soldered".  Any information would be greatly appreciated.


Cheers.

[bud16415]

It only takes the slightest current draw to trip a GFCI and it will trip way before the heater would have a chance of burning out with a short. So it could be the heater and it would measure good in terms of resistance and even a short between the housing and the element. Something like a megger would be needed to see if there was a break in the insulation. Sometimes moisture on the surface will transfer enough current to one of the posts to trip the GFCI.

Wish I could help more but it sounds like you have the problem isolated to the heater. 

[Tman122]

Hey there folks.

The heater was showing continuity and the proper resistance but the GFCI would trip when connected. With the heater disconnected for troubleshooting, the lower tandem relay wasn't passing voltage through it when the heater light was on, so I assumed it was toasted. Pulled the board, replaced the relay and the one above it for good measure and reinstalled everything. The new heating element still showed solid resistance and it wasn't in contact with the heater tube.

GFCI tripped again. 

I replaced the heater assembly (sensors and element) with a spare unit that I picked up for a good price, just for trouble shooting, and the tub fired back up.

Went through its internal tests successfully and then resumed normal operation for about 2 minutes and then tripped again with the same outcome. 

Everything else seems to run normally (circ pump, ozone, jet pump, light, and blower), GFCI stays powered with everything but the heater hooked up. Even the heater terminals are showing 240-250v when powered. In both cases the heater still showed good continuity and resistance.

Is it possible I've tested 2 bogus heaters or is something else at play here?  None of the solder joints on the board looked burnt or "cold soldered".  Any information would be greatly appreciated.


Cheers.

A tech may have a test board and/or heater, but you will likely have to pay a minimal fee. About 125 bucks around here. But they have access to parts and trouble shooting knowledge, maybe have him fix it for a couple hundred??