I wouldn't know what problems exist without checking the system but will say dirty blower and/or restrictive duct doesn't sound correct. Both would have prevented cooling during summer heat. Only a shot in the dark but worth a try,set t-stat to OFF and blower to ON for 4+hours in attempt to defrost coils. I believe you will have to hire a secound contractor if you still have trouble cooling and/or heating.

I wouldn't know what problems exist without checking the system but will say dirty blower and/or restrictive duct doesn't sound correct. Both would have prevented cooling during summer heat.

Thanks for responding Klem...could you clarify above? You say that a dirty blower would NOT prevent proper cooling when outside temp was 78?

A dirty blower will affect your A/C's performance but not by much. The A/C should still keep the house cool but the dirt will make it work harder than usual. I think you should have another contractor re-asses your system. The other guy definitely missed something.

I know I am stating the obvious, but I am sure you or someone checked and replaced all filters. Also, you didn't get one of those super Merv filters that don't let anything through - including air? Might try running without a filter for a short time just to see if it works better.

Also, do your ducts run through the attic? Did anyone check your return ducts? Maybe something opened up and it is picking up warm air.

This post was edited by Dovetonsils on Wed, Dec 3, 14 at 14:57

Thanks Dove. Will see if return ducts were checks. And yes, the second guy said our filters are too restrictive...although we have had them for 4 years without a problem.

the blower wheel would have to be extremely dirty to not cool. get the coils chemically cleaned and or recover all the freon and do a deep vacuum on the system and things should be good.

Here is a link that might be useful: HVAC info