Jag har samma problem med, har inget med termostat att göra.
Jag gissar på skitig olja och eller vatten.
Men popen är höga och obehagliga. Smäller till i plåten.
Skall kolla hur det löser sig med ny olja.
Från Reddit
It's moisture (water) from the food.
Science: Oil is less dense than water so when you place anything with water into oil, the water will sink to the bottom. If your oil is really hot and there's a large quantity of it, the oil superheats the water and causes a steam bubble. This bubble moves rapidly to the top and is the cause of your "hot popping oil"
Get an oil thermometer and monitor your temperature.. It also helps to use a container with higher walls.. It always pops but it's not nearly as menacing if the oil can't spill out..
Splashing water onto oil tells you very little beyond the fact that it's hot. It could be anywhere from 300 or 400+ degrees F. If you're on the high end your food is going to fry very quickly and pop more violently. Using thermometers will give you more precise, consistent results. Essentially you can tweak and adjust your food to your preferences and your food will eventually end up tasting better.