I know this has been asked already...But

[Spaniard]

I understand what you are saying What I don't understand is why the thermostat doesn't do the work of going up or down depending on the room temp.If I have the thermostat set to 92 even if the room temp changes why doesn't the thermostat do its job?Why do I have to manually change it?
Thanks Mike.

Assuming your thermostat probe in on the heat tape. Lets say you set it up when your room ambient temps are at 75. You figure out that setting the thermostat to 92 gets you 90 degrees in the tub, now your temps drop in the room to 70. 92 degrees at the tape now only gets you 88 degrees in the tub; the difference of 4 degrees can be attributed to the ambient air temps. No matter what your heat tape will only reach 92 degrees. Not sure if that cleared anything up but I tried.

Edit: The only way for you to get the thermostat to accommodate for changes in the air temps would be to have your probe inside the enclosure. Since this could cause major problems if your snake dislodges the probe almost everyone places it on the flexwatt.