I have an Aquastat L4103A 1100 on my oil-fired water heater. I'm trying to lower the set point, but I can't seem to get below 140F. There aren't many gradations on the set point dial. There's a HOT, NORM & WARM on one side of the dial and 180F on the opposite side of the dial. I've moved it below the WARM setting, but it's still too hot.
Does anyone have any insight to where the dial should be set?