My question is what kind of temp reading should I get when I place a temp probe into the duct work right at the main trunk just outside the indoor unit? I am getting 72dF. I just wondered if that is close to normal. I have a 10 yr old Lennox combination heat pump / ac unit. I live in PA and its about 93dF now.
well you either measured the return air, its really hot in the house and you just turned on ac or you have a problem
Unfortunatley there is no good answer to that question but I will suggest this... you arent going to cool the house down with 72 degree air unless you are moving an awful lot of it (meaning more than any reidential systme can move). Odds are if the system is running (indoor and outdoor sections) that 72 degrees is not right, you might want to get it checked.