I have a new home and I'm pretty sure the a/c isnt working properly. I live in chicago and temps have been hovering in low 90's with high humidity. I have a 3300 sq ft housing with separate furnaces and a/c units for each floor. They are all frigidaire furnaces and a/c units. The lower floor cools great. It will cool the floor in 15 mins and then shut off. The upper floor however seemed to work fine until the temps climbed. Now if i turn the a/c on it runs forever and never goes below 76 degrees. I had a tech come out and he said the one unit that was the lower floor had pressures of of 250 on the high side and 75 on the low side. The OTHER unit that wasnt cooling well had pressures of 175 on the high and 85 on the low. He thought the valves in the compressor were bad and needed to be replaced. He couldnt fix it as he wasnt a dealer for frigidaire so I called the guy who originally installed the system and since all the parts are new he didnt think the compressor was bad. He looked at it and he removed freon to get the pressures in line and said it should be ok. It is very slightly better but certainly not like it was! Was this a line of BS? Should I have someone else come look at it? My return temps measure right by the filter were 71.5 and the discharge right at the top of the furnace was 56.5 on the bad one and 71.1 over 52.5 on the good one. The cool air coming out the registers upstairs was 65 degrees on the bad one and 58 degrees on the lower floor. Any ideas?? Thanks alot for your help!! bob

Hello, This is my 1st posting. This is a long posting but I have many questions. I appreciate all the help in my questions trying to fix/replace my AC and furnace. The previous owner installed a Lennox AC (model HS29) and furnace (model G24M3/4X 100A). During the last heat wave 2 weeks, I found out that my AC is not working. The next heat wave is coming. The fan on the AC unit outside is running but not inside the house. When I switch to heater, the fan inside does work. Called an AC service repairmman and he mentioned that the PC board is bad. Does this sound right? What else would cause this problem? Unfortunately, the existing Lennox PC board (#33J6201) is not made anymore. Lennox replaced it with new model #65K07. If I want to replace new PC board, it would cost me $200 for part + $300 for labor because new board require major installation work. Where can I find the old model of the PC board? Usually how long do these PC board last? Is it normal for the relay component to go bad? The label on my unit said "1st Service in 1996". Can I fix this board myself? Where would I start? Lennox does not sell directly to consumer and they don't have the old model anymore. He suggested that I replace the furnace with Trane and keep the existing Lennox AC. Is this compatible? What issue(s) would arise if I do this? Usually how long the furnace and AC last before you need to replace with new ones? If I have to replace new AC and furnace, what brand would you recommend? TIA, Melissa