Well I chickened out... When I saw that I had a plastic drain valve.... So I'll need to get one on hand before I drain it. But just out of curiousity, I went and shot some water out of the faucet for 1 minute. It was registering about 162-4 when it was set at 130 F... I turned it down to the next notch. Will check it tomorrow. But upon reading on the robertshaw gas manifold, I was seeing about the calibration. One of the side items I saw is that the tube that goes into the tank I guess is liquid filled and can loose fluid over its life causing out of calibration reading. Interesting side note.
Sometimes just moving the control up and down the temp scale a few times is enough to clean the control. I "fixed" the temp control on my mom's Amtrol Boilermate that easily about 5 years ago.
