This post will be long but possibly very informative since I've seen other similar Leisure Bay posts. I am also in need of professional advise as I'll point out a possible problem and defer to the experts on possible solutions.
First off I pulled a bonehead stunt when I put a hose running full bore into my 2002 Leisure Bay Flores Spa to top it up and then walked away for ten hours. When I discovered the waterfall coursing over the side of the spa I also found the GFCI tripped. After bailing down to normal levels attempts to recycle the breaker caused an instant trip.
So I opened the Control panel and it was dry, with the exception of the bus type fuse in it's holder at the bottom of the box. I blew this all dry with my compressor but the GFCI still trips. I pulled the heater leads from their spade lugs and the GFCI holds and the spa operates normally (with the exception of no heat of course). Touching either heater lead to its lug on the board instantly trips the GFCI with both s3 and s4 high limit relays cycling on the board.
Now I suspect that I've fried the heater somehow. This is a 4 KW heat exchanger type heater made, by RMF part # F2400-1001, for Balboa. I take a resistance measurement through the leads and get 15.9 ohms. There is no continuity from the leads to the heater housing. Seems normal to me.
Now I proceed to pull the heater assembly. This is where things get interesting. This heater straddles a aluminum box with the box having U shaped cutouts on both ends that cradle the heater tube. Three aluminum straps hold the tube in place. When I removed the straps and then the heater tube I discovered that this is a free flow tube with four 1 KW linear elements that are integral with the exterior of the tube(No immersion element). This is probably not the most efficient heat transfer but the elements are immune from corrosion. Each element has a short ninety degree turn at each end with electrical pins protruding from each element. The four pins are bridged together with a steel bar. Electrical leads on opposite ends are mounted to these bars. The elements and connections are oriented at the bottom of the heater tube.
The elements and electrical connections are on the outside of the tube (and thus exposed). This is why the tube straddles the aluminum box with the electrical components in the box, to protect the high voltage connections.
Anyway, apparently the Balboa people glued a strip of foil faced insulation over the heating elements (to increase their efficiency I guess). This strip was then taped on one of the long sides with aluminum duct tape. Don't know why only one long side.
I found that this insulation was soaking wet and so heavy that it had pulled off the elements and was hanging down against the electrical connections, 240 volts and all. It was still stuck fast to the one long edge by the aluminum duct tape though. This grounded the electrical connections to the heater tube, the box it sits on, and thus the spa pak housing etc. So I removed the soaking insulation and replaced it. I figured I had found the culprit and thus the solution to the GFCI tripping. I put it all back together and voila the GFCI still trips instantly. Same problem with the s3 and s4 high limit relays cycling, followed by instant trip.
So now I need some professional help. There is one last piece of the puzzle that dawned on me. Under one of the straps, that hold the heater tube to its box, there is sandwiched a temperature probe of some sort that is in close contact with the heater tube. I assume this is a over temperature probe or maybe the main temp probe for this spa. Nevertheless,if voltage was shorted to the heater tube then it would have passed through this probe and possibly traveled through its lead to the circuit board. Tomorrow I'll disconnect this probe and see if the trip continues. I don't know if this will help anything as I'm not real clear if this damaged the board on that particular circuit. As I stated the spa works fine until I connect the heater. Any enlightenment would be appreciated. Thanks

The insulation got soaked, and likely created a small amount of corrosion on the heater poles. This element doesn't actually come in contact with the water.

If cleaning and drying of the poles doesn't fix it, you need a new heater. They're around $250.

EDIT: Just wanted to add, the hi-limit temp sensor has nothing to do with your problem, and not getting any OHM's from pole to ground isn't an effective way to test for potential current leakage.

Good luck!!

~Swine

+1

Those elements rot out all the time because of the stupid insulation blanket.

Replace the heater.

http://recreationalfactorywarehouse.com ... ion=Search

Unless you're skilled/crazy enough to do this:
http://spapartsnet.com/chemfreemod/

I've flipped the assembly upside down, drilled two holes into the case with a stepper bit, then installed a standard 4.5kw heater element. Yippee, no more $249 heaters.

I've done 3 successfully. Had a customer of mine do one himself successfully as well.

ymmv.... use at your own risk.

Thanks Swine and Pageup
Hell yes I'm skilled enough, and crazy enough as well. I hate to throw anything away and have fixed things that most would toss. I was afraid that the heater replacement was going to be necessary after checking out the GFCI Tripping Forum. I was stunned when I found out what that baby costs though (found out immediately after I killed it). I did find it for $150 but even that seems steep. Can you hook me up with a link to the element that I would use? Does it come with the gaskets for the install? So far we haven't had any prolonged bitter cold here since I killed the spa. I sure miss our spa though. Maybe I can sit in the tub and have my wife stir the water. Not likely though since right now she'd rather strangle me. Steve

Here it is

Where did you find it for 150?

SpaPartsNet.com
Search Spa Parts: Balboa 58042
Hey, about the hardware in the conversion pics. Are the bolt and washers setup just to crush the tube flat where the element contacts pass through the tube?

Yep- the tube, washers and O-rings will seal up if you tighten enough
btw- 58042 is not your heater. 58042 is a 2" flow though- the S2/G2 is a 2.5" heater

Hmmm
Interesting about the heater. That # was on a tag that was on the tube. It was a Balboa tag that was separate from the RMF manufacturer tag. Otherwise I'd have never had that number. The RMF part # was F2400-1001. I thought it was too good to be true. The best price I found otherwise was $230.00 but that appeared to be the entire assembly including the box that the tube is strapped to. I assumed the 58042 was for the tube alone.

My memory stinks lately, maybe page-up will correct if I'm wrong- now where did I leave my car keys?

Swine
If you look at image 100_2156.jpg upside down you can actually see the tag with that part number on it. There is a top line that ends in Leisure Bay. Under that is the UPC code. Under the UPC code is a line that starts with 58042 and the rest I can't make out.