Something is wrong. My water was also around 50 degrees from the hose, but I was up to 102 in five or six hours if I remember correctly. I know for sure it was same day.
My Electrician did the same thing on my Grandee.......Love our tub......enjoy!
Aha!
The spa tech was just here. Seems the electrician hooked the power supply fr the heater up to the wrong terminal in the spa control box. He swapped the wire over, turned on the power and "click" on came the heater.
Now the wife is calling the electrician to give him hell and see what he intends to do about it. At the very least, we are not paying full price for the job. I feel bad for the poor guy, even I'm scard of my 130 lb woman......