An inflatable hot tub, to state the obvious, is filled with air and air is actually a very very good insulator. Think about double glazed windows. What makes them effective is a layer of air. We have already noted earlier that inflatable hot tubs have thick sidewalls, up to 10 inches thick. This actually provides great thermal protection from heat loss on the sides. Couple this fact with some insulation underneath the hot tub and a decent cover and you have a hot tub that is reasonably well protected from heat loss. Not as good as more expensive models but not to shabby either and one that can certainly be managed.
The third most popular complaint was over the heater. Many customers were disappointed that the heater automatically shuts off after three days of continuous use. Although it is considered to be a safety mechanism, it was quite annoying to many customers that didn't want to lose the heat in their water and then have to repeat the process of reheating it again.