High limit switch replacement?

[oberkell]

Jacuzzi Caressa model 8780000

I inherited the above-mentioned hot tub in the house we purchased.  After replacing a cracked jet and a few tees and lines, I started this beast up.  I set the temp (old dials) and the water heated up fine over night.  The system filter/heat selection works fine.  Replaced the filter. Tub starts up if the temp gets too low etc.   But, when I turn the jets on the system shuts down after Appx 2 minutes.   I reset the 30 amp button on the electrical box to get the system back and running.  I try to reset the high limit switch, but it appears to be stuck.  I can't push it in or pull it out.  I took the housing off and pulled the bulb out (how far does it go in the tube?)

I assume I should replace it, but it seems strange it will work fine without the jets.  Do thejets increase the temp?

Thanks,

Rick

[Dr. Spa™ Ret.]

If the high limit hasn't tripped, it can't be reset....nor can it be pulled out. Sounds like it's fine. The 30a breaker it tripping because it's either failing (unlikely), or the entire spa is pulling too many amps (more likely). This has NOTHING to do with temperature.

[oberkell]

Thanks for the reply.   The system has been converted to 4w, 230v, 50amp.  Since the 50 amp breaker or gfci doesn't trip, I assumed the motor is overheating when I turn on the jets.  Because the 30 amp circuit protector switch on the SCM trips even on a lower temp with the jets on.  Could it be a relay?  I guess I could just be content with it working on the heater/filter mode, but the wife insists on the jets working.

[Dr. Spa™ Ret.]

It could be this, it could be that, it could be something else....I doubt it's the pump overheating (motors have their own built in high limit switch).

You could just start replacing things, and by trail and error you'll probably eventually replace the defective part. You might consider calling in a professional service tech...probably fix it for 1/10 the cost of trial and error guessing. Assumptions tend to get rather expensive, unless one is very lucky.

[oberkell]

That's what I was afraid of.  Seems like this tub was made by kawasaki.  My 77 kz1000 was a delight to work on. 

I think I will start with the relay.  Maybe it is sticking.