Originally Posted by
DRL
Just a guess, could the location of the temperature probe explain this phenomena? Or...when the shutter is closed, the vernatherm senses hotter oil, it then opens, increasing circulation and that gives a cooler indication. It seems your indications are a result of the interaction between the temperature probe, vernatherm and the shutter. You may have to take out the vernatherm to see what is actually happening.
We have taped ours, but we are considering installing a vernatherm. The shutter may be better, so we are interested in how yours works. Husky's use a manual air blockage system and it seems to solve the problem.