I have a Cal-Spas v-500 hot tub that I bought new in 2003. It has been shutting itself down with the OH error code which means overheated sometimes it might do this 3 or 4 times in 24 hrs. I have to push one of the buttons to reset so it will start heating again, I checked the temp of water and it is very close to the display setting of 100 degrees. Last Sunday I took the filter out and since that time it has only kicked out one time, The filter is not that old only been used a couple of months, The spa does not have a heavy user load, and this problem started last winter. We only have water in it during the cold weather. It is inside a enclosed deck with no heat or insulation.
Does anyone have any ideas what might be wrong with spa?
thanks