Just putting this out there for others. I had my aquastat on the storage tank, with the short capillary tube (maybe 6 inches) so that the dial to set temp, and whatnot was mounted pretty much right on the tank. Foamed around it. WELL.. as it turns out.. that area is WAY WAY too hot for the unit. I saw some specs online that the max ambient temp was much lower. Now, I'm not positive that my unit was sticking due to heat, or sticking due to the blow in cellulose getting in and around the contacts. Regardless, I moved it to a remote bulb one. Came with about a 5' tail. Now I can set the temp without opening up my access panel ( and making one heck of a mess with cellulose fiber) Be careful not to kink the capillary tube when installing. I wound some big circles and tucked it in where it was protected from the plywood when I closed it up.