Greetings:

Two years ago I purchased a used sundance suntub (dealer called it a Bali?). We fixed a few leaks and it would heat up to 108 (which we wanted). The heater failed last winter, and a replacement worked fine. However upon firing it up this week it does not want to go above 102.

Specifics:
Controller box: Spa builders Support group
63758 RC0031G525BH-3
Product: 3-80-0103
Make: Sunpack 400
Serial: 970805026
115/220 (We run it all as 115V)
15/40 amp, 60HZ

In the box the board has this information:
P/N 6600-032
S/N 3TBS 3604
6600-910972
Rev. B

The clock works, though it does buzz. Particulars on the clock are:
FM12STUZ-L
01.76.0143.1 German
0.1A 125V 20T85

This appears to be an all digital setup, no mechanical thermostat. I can hear a relay/switch working as we rotate the topside temperature control. I can see the thermistor/thermocouple in the wall of the tub, and I can feel the hi-limit wires going to the heater. On the back of the black box is a large, transformer sized box that is attached to the heater. It gets warm when heating the tub up.

So, any guesses as to why we can not get a higher temp? We need at least 104-108, 102 will not cut it. At one point (with original heater and with hotub in heated garage, the tub made it to 118....which my girlfriend liked...but not me). Even when the tub was moved outside it would reach 108, even in the winter up here (Alaska). Unfortunately at the moment it is a balmy 60F outside but the tub can get past 102. That does not bode well for this winter.

The pump works fine, and everything else seems in order. Is it a bad hi-limit switch, or the thermocouple/thermometer? How can I check them out, or do they just get replaced (I can use a VOM)? Any suggestions would be greatly appreciated, winter is coming.

Thanks

Sean

Doesn't want to go above 102 eh? Me thinks the controller probably got a little more intelligent with time. CPSC federal mandated maximum is 104. If you want to get rid of that and work with something that you can 'calibrate', to suit your needs within an 8 degree range, then I'd recommend: http://spapartsnet.com/Spa-Packs-Controls/ACC Anything in that line can have it's sensors recalibrated from the top control panel.

Must be japanese type that likes to sit in crock pot. But 118 is dangerous and the tub should have shut down - that's way too high no matter what your girlfriend thought. That controller is literally out of control, is unreliable due to it's make/model/age, and needs to be replaced. Anything of that age with Spa Builders name is a dead deal to work with. At this point I wouldn't trust it as far as I could throw it.

Thanks for the prompt reply. Since this is a used tub I do not know its history of repairs. Can you tell from the information I posted that the control pack is pretty old? Do all the control packs fade with time (this appears to be all digital), or just that brand?

I recognize that the easiest fix maybe to get a new controller, but that is out of the question ($) for now. Given what we are now seeing for a temperature range, is there something I can check to verify that the hi limit switch is working properly, and that the thermometer/thermocouple is functioning correctly as well?

When I checked the site you linked it appeared all the control packs come with heaters...I just put a new heater element attached. Are there controllers available that do not have heaters attached?

I appreciate the feedback

Sean