This is an older CalSpa. I do not know the specific model number or controller number but it has air controls in a large black box with a 2" metal tube below with the electric heater in it. The thermostat dial is top mounted between the air controls and the temperature sensor is in an elbow just prior to the heater. There is an ozone tube that is not hooked up (it was disconnected when I got the unit and I can't seem to figure out where it is supposed to plug into). The black control box has a GFCI in the face as well as a switch run in freeze protection mode or off the timer (also in mounted in the box). I got the hot tub about a year ago for free. the frame was rotted and it didn't have a cover. I rebuilt the frame and even found a couple of leaks. After fixing those but before sinking more money into skirts and replacing insulation I decided we should fire it up and see if it ran. Filled it, heated, and balanced chemicals and used it for a couple weeks without any problems. Then the GFCI that is in the control box started tripping. I would notice it about twice a day that it had tripped. It took about a week to catch it trip as it would never act up when I was working in the area. Finally I caught it as the heater was coming on. Over the next few weeks I could occasionally get it to trip with the heater control and that seemed to be the common thread. I suspected a problem with the heater or the control. Now up to this point the switch had been left in freeze protection. I decided to flip over to the timer and test that part of the system to determine if I had other problems. The GFCI did not trip in timer mode for up until I drained it a couple of months ago. During that period if I flipped back to Freeze Protection within a few days the GFCI would begin tripping again. I am suspecting the switch is faulty the controls between the timer and the thermostat to run the pumps. I didn't know if anyone else had this issue before or other thoughts before I replaced this switch. We are coming into winter soon and I would like to know that the problem is resolved before it gets cold and I have to watch the temperature. Thanks Tim

I would suspect the heater element. If you disconnect both wires going to the element and isolate them from touching anything, and try all the modes, that will tell you if you found the problem.

I had wondered about the heater initially but when I put the machine into timer mode the heater came on and off without any problems at all. Over the weekend though I got a chance to get another similar tub for free for parts, so I will check the heater once I start things up again. Thanks Tim

For more information regarding the timer, heater and schematics of this box, I would suggest to speak to the Cal Spas Technical Support at 800-225-7727 ext 753. They can trouble shoot your needs and work out a resolution for you. Although, Cal Spas no longer supplies that older style control box, you may also contact a company called PLASTEK at 909-353-8005 and they may also be able to trouble shoot or supply any necessary parts for this control box. If you need anything else, please give us a call. We're here to help you with all your home resort needs.

- Customer Care Supervisor for Cal Spas