I have a Sundance Optima above ground Hot Tub, 850 series model that was purchased in 2002. I recently cleaned, and installed a brand new filter and successfully enjoyed a few times prior to this current issue. It appears the Hot Tub display "thinks" it's at the desired temperature, when it is not. There are no error messages on the display. When the temperature is adjusted higher, the display shows the heater being activated and attempts to heat up. When I stick my hand in the water, it feels about 30-40 degrees cooler than what the display reads. I can feel some pockets of warm water.
I'm hoping the issue is with the thermostat, and not the heater, but I'm not certain. Any direction or suggestions would be greatly appreciated.
Thanks,
Eric V.