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 continuinity and the proper resistance,  it 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 as well) 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. 

 

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. 

 

 

[RDspaguy]

Sounds like the gfci to me. 

If the heater is tripping it for a ground fault you will get an ohm reading from the heater terminal to ground. Disconnect the heater wires and test it. 

A breaker going bad will often trip under heavy load but not under a light load (like when the heater is not on). A gfci fault will usually trip immediately, with your hand still on the breaker, as one leg of the heater turns on immediately.

[johnovision27]

Thanks for the reply RD.  
I may just have to pick up a new GFCI for troubleshooting and see where I land.  

For further clarification, when it was tripping, it would trip immediately when turned on, and I can confirm that the RED hot line heater relay was clicking on and off as this happened.  So, what you're saying checks out.   Just seems odd that it worked for a few minutes with the other heater installed.  

I'll post back with any news.  

[johnovision27]

I went through all the connection from the main panel back, and a few of the lugs on the GFCI were a little loose. I tightened those up and put a replacement heater in just to make sure. 

 

She's back up and running. 

 

Unfortunately, I can't definitively say what the issue was, but I doubt it's the board. 

 

 

[cranbiz]

The loose connections on your GFCI were most likely your culprit.