I've recently moved into a 15 year old house, with about 3000sf on 3 levels. There are 2 AC units in the house. there's a 2.5 ton newish unit, which services the lowest level of the house, which is about 1500sf. This unit is working well. There's also a 4ton unit original to the house, which services the 800 sf kitchen/dining/living level and the 600 sf upper master bedroom level. The house also has a fairly significant amount of window, something like 300sf of glass on the main open level and 150sf in the master bedroom. Almost all of it facing east. The main level also has 14' ceiling. All ductwork for this unit runs in an inaccessible attic.
That's all background. Since the weather's started heating up to the 90s and low 100s here in central indiana, the 4 ton unit has been running about 18-20 hours a day, and isn't keeping up. by about 5pm every day, the temperature in the master bedroom is in the mid 80s.
I've had 2 separate repair companies out to look at it. Both have come through our home warranty company, who requires that they pick the contractor. The first repair company checked refrigerant pressure (said it was fine), and the temperature at the vents, and then just said they thought it might need to be cleaned. Not a whole lot of diagnostics. I had the second company clean the outdoor unit, and they also tested pressure (also said it was fine). This time, they also mentioned that the contacter was fried, and ended up replacing the outdoor fan motor, contacter, and capacitor, because they said the fan was periodically stopping from overheating.
The problem has continued since then. So, since working through the warranty process is cumbersome, I'm trying to narrow down whether this is likely a repair issue or just a bad design, and what I should ask for when trying to find someone who can figure out what's going on.
I did take the cover panel off the indoor unit, and measured the temperature on the hot/cold side of the evaporator coil. it's 85 degrees on the warm side, and 45 degrees on the cold side. But the air coming out of the vents is 65-70. Is this normal? 20-25 degrees heat gain in the ducts seems like a lot, but I've been known to be wrong before!
Any ideas?
That's all background. Since the weather's started heating up to the 90s and low 100s here in central indiana, the 4 ton unit has been running about 18-20 hours a day, and isn't keeping up. by about 5pm every day, the temperature in the master bedroom is in the mid 80s.
I've had 2 separate repair companies out to look at it. Both have come through our home warranty company, who requires that they pick the contractor. The first repair company checked refrigerant pressure (said it was fine), and the temperature at the vents, and then just said they thought it might need to be cleaned. Not a whole lot of diagnostics. I had the second company clean the outdoor unit, and they also tested pressure (also said it was fine). This time, they also mentioned that the contacter was fried, and ended up replacing the outdoor fan motor, contacter, and capacitor, because they said the fan was periodically stopping from overheating.
The problem has continued since then. So, since working through the warranty process is cumbersome, I'm trying to narrow down whether this is likely a repair issue or just a bad design, and what I should ask for when trying to find someone who can figure out what's going on.
I did take the cover panel off the indoor unit, and measured the temperature on the hot/cold side of the evaporator coil. it's 85 degrees on the warm side, and 45 degrees on the cold side. But the air coming out of the vents is 65-70. Is this normal? 20-25 degrees heat gain in the ducts seems like a lot, but I've been known to be wrong before!
Any ideas?
