My problem is that my spa won't get above low 80s unless it runs for hours (at least 4 or more). I believe it is caused by the location of the heat sensor. Specifically, the heat sensor is located where it measures the temp of the water after it leaves the heater and is pumped back to the spa. So, it is measuring the temp of the water FROM THE HEATER and not the temp of the water IN THE SPA. This is causing my heater to turn off before the spa reaches the proper temp.
So, if my desired temp is 102, then my heater turns off once the water FROM THE HEATER reaches 102. Not when my spa reaches 102.
Therefore, my theory is that the location of the heat sensor is limiting my ability to heat my spa to the desired temp.
A little more background...
a) This is not a new problem...it's been like this since I've owned the house (2 years) and I don't know what the experience was for the previous owner
b) I confirmed that the heater is working properly. I did this by placing a thermometer in the basket of the pump and confirmed that the water coming from the heater and getting pumped to the spa is 102
c) I've experimented with turning the spa jets on/off and also manually churning the water (to try and force cooler water back to the heater...just to see the effect)...there was no meaningful impact
1) Is the heat sensor for the spa located in the proper location (or should it be located where it would measure the temp of the water FROM the spa instead of TO the spa)?
2) Is it okay to move the heat sensor or would moving it make it "not up to code"?
3) If the heat sensor is in the proper location, why wouldn't this be an issue for every spa owner?
4) I have a VS pump and for "Spa Heat" it runs at 2650. Should I increase, decrease, or stay the same?
Any advice would be great. Thank you TFP community!