David, welcome to the board, I take it from you posts that you are a HVAC tech. Could you give us a little of you background on yourself so we can put your comments in better perspective? You can go into the profile section and give as much or as little information as you like. For instance, since there are regional differences due to climate, etc. it helps to know what part of the country you are from.
Thanks for participating, I think most here on the board are ready to learn and readily admit we don't have all the knowledge.
Jim

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Jim Luttrall
Mr. Inspector.net, Inc.
Allen, Texas 75002