one thing i could add , i was doing some duct work on my garage oil furnace today a used one i bought and i could't keep my hand on the sheet metal ( clean air out) while it was running ( to hot) i'am pretty good with guessing temps with how long i can keep my hand on a surface but just to check i got out my fluke and like the other guy mentioned it was all over the place with shinny metal , no matter how close or far i got , so i got the direct contact wire thermocouple for it out and it was running at 175f way hotter then i wanted or thought . after some investigation i found that the fan speed was set to medium , so i reset the wire to med hi and it brought the temp right into 140f (perfect) which happens to be the temp i can keep my hand (palm)on the metal. guess im say wizz if you can keep your hand on the stat houseing your motors too cold , if you can keep it there for maybe 3 sec's it might be 150 , if only 1 sec it might be 170 . ???? we all feel pain different but you get the idea ! give it a try ! keep a cold beer in the other hand just in case !! later have a good day.