If you buy those $10 digital oven thermometers and use them in any kind of liquid the probes die very quickly. The problem is that liquids get in there and corrode the fine wires and the thermister, causing it to stop working or read very strange values.
I made a short video about how to solve this problem yourself in about 10 minutes.
- Silicone gasket maker (For automobiles)
- Heat shrink tube. I use two pieces. The first is small, just big enough to go over the probe and around the bend. The second is big enough to cover the first.
- A lighter or heat gun to shrink the tube. (Duh!)
This won't help you if the plug-end on the box is corroded or loose, the other general problem. If wiggling the plug in the thermometer makes the temperature read correctly, this won't help.
I recommend you do this to the probe as soon as you take it out of the box. If you put it off and any liquid gets down the probe hole this probably won't help after the fact either.