The Risks of not Using a Thermostat

The picture above is of a one foot piece of 11 inch wide flexwatt that has been severely burned.
Please be aware that this is not a common occurance by any means, in fact this is the first time I have experienced it in 10 years of using flexwatt. The point of this page is to make you aware of the possibility, which no matter how slim is not worth taking the chance.

I built this cage which was identical to several others I already had in use. I installed the flexwatt inside the cage, as is my normal procedure. I didn't have a thermostat or dimmer on hand but elected to go ahead and put the cage into service since the snake to be using it was small and had plenty of room to move away from the heat.
Ventilation was adequate as well, so in my opinion overheating of the cage from the normal maximum temperature of 110°F reached by the flexwatt, would pose no real threat of endangering the snake.

I am unable to determine the nature of the malfunction, but the heat tape overheated to an extreme degree. For reference, the tape was properly wired, and no staples were used to secure it, so an electrical short was not the cause of this.
The substrate in the cage was cypress mulch, but it was a thin layer, and the trapping of heat is not plausible.

I entered the snake room and smelled a faint scent of burning wood. On this initial detection, I could not locate the source of the smell, and it was so faint I assumed it was coming in from outside through an open window. This action could have easily resulted in a disaster, but fortunatly it did not.
The next day, I went into the room and still smelled the odor. This caused me to check thoroughly and I discovered this heater.

I unplugged it immediately and got a Raytec heat gun to determine the temperature. I got a reading of 192°F at the hottest spot. The melamine floor of the cage was also burned and will have to be replaced.

I'm sure at this point you can easily see not only the danger of killing the snake, but also with the floor of the cage burned, the very real danger of setting the house on fire. Thankfully, neither happened.
Some may call it plain luck, but I call it the grace of God that I still have a roof over my head and a collection of reptiles to care for.
I suggest all of you heed this warning and use thermostats.
Many times in the desire to add another herp to a collection, money is used to pay for another animal and caging issues are set aside. Even if it means not getting that next herp you are wanting, put all your flexwatt heaters on dimer switches at the very least, and thermostats if at all possible, since thermostats will cut off the flow of electricity completely after a set temperature is reached.

As an economical thermostat, I like the ZooMed Repti-Temp 500R. This is a nice little unit and is much more affordable that the proportional thermostats I also use.
I have price compared this unit from many places and you will see them for as high as $65 each. This is a rediculous price and I fear those who see it will write off the possibility of using these thermostats.
You can get them from for $27. Free shipping with Prime. Click below to save a search.
ZooMed Repti-Temp 500R

I do not want this instance to result in discouraging anyone from using flexwatt, I have no plans whatsoever to stop using it. I just want everyone to be aware of the potential for this happening. As I said, in 10 years of using these heaters, this is the first time I have ever witnessed any sort of malfunction. However, a problem of this type can result in disaster on the first occurance, and I never want to hear of someone losing animals, or worst of all their homes due to this small oversight.