This is the second time my chiller has "eaten" the thermocouple that controls the cooling. The "soup" is very caustic and dissolves the chrome plating, then attacks the active element. The result is the chiller getting a bad signal, and cooling the soup even more. The plant loves it, but the condensation on the plumbing makes pools of water from dripping off. I don't even want to think what my electric bill is gonna be. Replacement TC's are very cheap and available on Ebay.
Hopefully mine already are. They've been through a few grows, and I haven't noticed anything during cleanings. Can't say I gave thorough examination, but will certainly keep an eye on em.