Check it in ice and/or boiling water without submerging bent section where the wire goes into probe (that's where the water gets in). If it reads 32/212 or close enough to make you happy, you're fine, just keep it from getting water/wort/whatever in there. If the reading is way off, stick the probe in the oven til you see liquid come out and then dry up. Re-check. I found a replacement probe with stainless wrapped wire, but it cost as much as this cheap POS did in the first place. Found a candy thermometer with pretty good analog dial and a 10" probe for under 10$ delivered. I'll get one of those til I decide I want something fancier.