Question about GFCIs and heaters

[louis]

Moved into a new house and left hot tub at my house I was renting (not included in rent and as is).  Tenant called and said water would not get hot.  Went over and it appeared the topside control was bad as I could not read it and the plastic overlay was broken and there was water in the topside controls.  I didn't know if that was the problem or if it was the heater.  He asked me to fix it and I told him I would remove it instead (not being mean, but they were slowly destroying my house -- but that's another story).  So I moved hot tub from old house to new and wired 240 volt into tub (after it sat unused on pad until warm enough weather for me to work on it).  As soon as I turn breaker on, it trips immediately.  I wired exactly the same way it was at the old house, but it had been sitting unused for a few months.  I thought maybe I wired incorrectly, but everything appears the same.  It had always been temperamental with the spa subpanel (60a) tripping occasionally but won't even turn on now.  I have 60a 240 cb in main panel going to spa subpanel with test button.  To troubleshoot I disconnected the spa subpanel and turned power on and main panel did not trip.  So I attached back to sub panel.  Then I disconnected one wire at a time from the hot tub and when I disconnected either of the power lines from the hot tub (leaving them hanging in the air) and turned the subpanel back on, it stayed on.  I tested it with the 'test' button and it tripped properly and held its load.  But when I reattach to the hot tub it trips immediately.  I also tried unplugging the pumps and ozone plugs from the right side, but it still trips immediately.   I read somewhere in the forum that it might be the heater that went bad, but I am unsure as to how I would prove it; I don't know how to isolate heater to check it (plug or c/b).  I have a hydroquip CS6230-vds.  My questions are:

1.  How do I isolate heater to turn on c/b and see if it stays on -- hopefully telling me that is what the problem is... or will it?

2.  How do I replace heater or do I need to just replace the entire control system?  Is either the heater or the entire change out something that I should even be trying or should I call a service tech?

3.  If I replace the entire control system, do these retrofit packages I see that are cheaper as good as the originals.?

4.  Is it better to stay with the 240v or go with one of the 120s.  I actually would prefer staying with the 240 since I have already wired.  Just not sure if I should?

I have a couple of more questions (like best cover, or can I make my own replacement), but first I have to figure out how to fix this thing or if it is worth fixing.

Spa is a Pinnacle with Hydroquip that I ordered on the internet from a dealer in FL back in 2002-2004 time frame (can't quite remember), and had it delivered to my house in MI.  I then moved it to NC in 2007 and now I moved it a 3rd time to my new house in NC (retired military -- used to moving).  Any help you can provide, or simple consolation, is much appreciated.

Lou

[bigjoe1]

The first thing I would check is the location of your load neutral wire. One the most common errors made when wiring up a GFCI breaker. The load neutral from the spa pack back to the gfci sub panel MUST be terminated on the load neutral terminal of the c/b.  Lots of people terminate at the neutral bus bar and this will cause the breaker to trip as soon as you try to send power to the spa. If this is ok then I would do a continuity test from one of the heater terminals to ground. If there is any continuity at all, you have your answer. Hope this helps and good luck.

[louis]

Thanks for reply. 
Load neutral wire is wired into c/b not bus bar (60amp midwest spa pack c/b set) with a pigtail wire going to the bus bar.  But it does trip immediately as soon as I send power to the spa. 

My next question is why do I do a continuity test from heater terminals to the ground?  Should there be continuity there -- to ground?  And if there is continuity, what does that mean... heater is bad?  I am an amateur used to learning how to do things myself (having successfully wired basements and 240volt circuits in the past), but I have never had a problem that I had to troubleshoot -- they always just worked.  And can heater be serviced or replaced or do I have to replace entire spa control pack.  I did notice that the terminals coming up off the heater appear rusted and I don't even think I could get the nuts off without breaking them.

[bigjoe1]

Sorry for not getting back to you sooner, yes if there is any continuity at all then the heater is bad. Normally all heaters are replaceable. Is there any way to disconnect the heater from getting power. If the C/B stays on when the heater is disconnected that will also tell you the heater is the problem.

[louis]

Thanks a bunch.  I disconnected the heater, where it was attached to the panel instead of the rusted bolt, and power remained on when c/b reset.  It appears that the heater is the problem and I think I should be able to change that out.  Appreciate all the help.