[JT]

Sorry to hear of your troubles. My instincts tell me (at this point) to suspect the thermostat. Mine came with a 180 'stat and last night crept to 190. Not critical, however I like to have more of a "buffer" particularly with the concern about air bubbles we have. Might I suggest dropping in a 160 thermostat, at least for a test run? A $4.00 thermostat is a cheap stab in the dark. Best of luck, nice to hear you have consistant, healthy compression. JT