tonypilot7

Well, just in case anyone else has this issue, I am posting what the problem was. The limit logic circuit went bad on both the upper control and the mainboard. The tech who tested it told me that something had failed on one part, and that ended up taking out something else on the other part... He didn't know which one died first and he got a different result with each test. We tested my upper with an operating mainboard with no luck, then tested my mainboard with a working upper.. still no luck. It would've cost me more than it is worth in hourly rate alone to find the exact chip that had failed and then replace them on both boards. I am going to retrofit a low flow spa pack into the tub and forget about these P.O.S. proprietary parts. P.S. I have two brand new thermistors and a used but still good heater for sale if anyone is interested.

well, new thermistors didn't fix it. I checked the new ones and they are giving almost identical readings, but the heater light still kicks off after 2 or 3 seconds. I measured voltage at the heater terminals right as I powered it up, and got 120-124 volts before the relay clicked and the heater light went out. then the voltage obviously dropped to 0. I am stumped.

As I was digging around online last night, I found a diagnostic manual for the IQ2000's here: http://www.hotspring.no/pdfs/I7.pdf There are a lot of owners manuals, some in German here: http://www.hotspring.no/pdfs The diagnostic manual confirmed that my thermistors aren't working correctly. The control panel isn't receiving a signal from the mainboard about the temperature, which made the control unplugged light come on initially. This also would cause the LIM light to go out. without knowing the temp values, the control panel won't send the heat request to the main board, so no heater light.. Hopefully when I have the thermistors in, that will fix it. If I missed something or you can think of anything else I can test, please let me know.. this is my first time diagnosing a hot tub, so I am figuring it out as I go.

I have been reading through the posts on this forum all day trying to find someone who has had the same issues as I am having, but no luck. So here goes: I recently inherited a tiger river Bengal spa and have been getting it back into usable condition. It was working fine this morning. It sat empty for 2 or so years and had a ton of gunk in the lines so I decided to run some spa purge through it. And yes, I almost forgot to take the filters out first. Halfway through cycling the purge cleaner through the different jet positions, I started getting a blinking ready light on the control pad. The PCB lights were all lit up including the control pad unplugged light. The funny thing is, the control pad still worked. I could adjust temp, jet pump and light with it. I decided to unplug the spa for a couple of minutes hoping the flashing ready light would reset, and when I re-powered the spa, the heater light on the PCB came on then shut off after 2 or 3 seconds, I could hear the relay click when it shut off. The lim light came on and then shut off about 10 seconds later. The control unplugged light doesn't come on anymore. The tub is losing temperature now (down from 102 to 92 in just a few hours). the heater is not coming on no matter what setting i have on the control panel. I still have a blinking ready light, and the power light is solid. Everything else works fine, circ pump is circing, ozonator is ozonating (bubbles from the center drain) jets jetting, tub light is ok, control pad functions.. I am wondering if I screwed something up by running the purge stuff through it. Hopefully one of the many people here who are smarter than me can help me to figure this out? EDIT: forgot to mention this has an IQ2000 control in it. wired for 115v. EDIT#2 water temp at 88-90 degrees, checked both thermistors: one at 7.6 and the other came in at 16.5 with my meter set to 20k ohms. Looks like thermistors may be the culprit, but would that cause the heater light and LIM light on the main board to go out? Also, I thought that these things shut off the jet pump and light when the temp sensors go out.. maybe I am wrong though. Also pressed the reset button as hard as I could on the heater, I don't think it was popped. Then I metered it and it came in at 10.6 ohms, so it's not the heater.