Well, its strange to me at least. I'm pretty new to all this hot tub and spa stuff, in fact this was my first time being involved with firing one up for the first time of the year. Anyhow, on to the details.

The spa in question is an older model Comfort Line Spa in a box portable spa. The pump went out on it at the end of last year, and since it was no longer under warranty a replacement was purchased but not installed until Late April this year. After installing the new pump and testing it I found that it leaked all around the seal on the front of the pump. Apparently the joint that my friend got the pump from put the wet end from the old pump on the new pump and there was enough of a difference to cause it to leak. Long story short, I swapped the wet ends and replaced the inlet and outlet hoses. Everything was bundled back in to the "Power Pack" and we fired it up. The flow was pretty low, but I didn't know how powerful it was supposed to be, and my friend couldn't remember if it was the same as always or not. The spa heated up in about a day, which seemed to be a normal amount of time. The only problem was that the water coming out of the jet was almost hot enough to scald. I then took the cover off the power pack and found that the hose that connected to the jet was kinked. Also the pressure switch was adjusted all the way down. After unkinking the hose and then adjusting the pressure switch according to some directions on the web, we fired it back up. Now there is no heat. I then went through all the troubleshooting steps I could find to make sure the pressure switch was working, and that the heater was getting power, and apparently all is well there but there is still no heat. The high limit on this model cant be reset (well it can be but there's no button, you have to run the blower until it resets which I did) The thermostat appears to be working as well, since you can hear it click on and off if you're turning the knob. But still no heat. I'm at my wits end here and think that it can only be a heater element or possibly the thermostat. I'd really love to get this up and running for my friend, because it was running earlier this year and it got used exactly 3 times. Any assistance or advice y'all can give will be greatly appreciated. Thanks in advance.

so check the heater and the thermostat and see if they are good or need replacement. use a multimeter and see with no power to the tub, and thermostat turned up, do you have continuity through the heater? thru the thermostat?