I have a 5 person SunSet spa that is about 7yrs old. I recently acquired this from my partens. I have had the spa running for several days now and can't seem to get the temp above 95 degrees. I was told by my spa tech to leave my spa on lo power to help regulate the temp, rather than turning it on and off. Even with my control knob turned up all the way I can't seem to get the tub hotter than 95 degrees. My partens have had it up to 105 and the dial was not on max. Thoughts?

Your tech should have replaced the thermostat first. It is a cheap and quick cure. Try turning the power off, remove any debris (leaves, toys etc.), remove the filter (s), turn the power back on after about an hour to let the system reset. Run the spa for a couple of hours with the knob all the way up. If the spa heats to 104 then just replace the filter. If not you will need to have the therm and pressure switch checked. A heater works like your hot water heat it is on or off not sometimes or a little bit of heat. Also have them check the power going to the heater to make sure it is consistent.