I posted on this last weekend and since then I have had an a/c engineer at my house twice this week. I live an hour outside New York City:
Problem: On 75-80+ degree days temperature will not cool lower than 74-75 downstairs and 78 upstairs. On 90 + degree week downstairs won't cool below 78 and upstairs 82. It runs non stop all day then when it cools down at night it can get down lower i.e. 72 (both up & Down) and works perfectly fine. It just can't seem to keep up when it gets hot outside during the day.
I have a Payne forced air gas furnace heating & Cooling system - don't know the model. Its 12 years old and installed by the builder. Have had numerous problems over the past two years. Outside unit is 3 ton - sq. foot of my home is about 1,700, two story, open floor plan. system has two zones one downstairs and one upstairs in a bedroom. Always cooled great up until the past two years. It could even cool the place down to 68 with no problem though I only had it that low maybe 4 times over the years.
Two years ago - it would blow warm air then completely shut down. This time its blowing cool air and not shutting down.
This is what they did two years ago and it worked great until now:
Two years ago: Technician indicated the we have a 5 degree F temp differential across the liquid line filter drier on the a/c. They said it indicated a restriction on the system so they removed our existing filter drier and in stalled a new one. They also removed the piston and installed a thermal expansion valve to improve the performance & reliability of the refrigeration system. This got the system up and running great for two years!
The technician told us this week that everything is running the way it should i.e. fans, condenser, filter is clean, pressures are normal, but the temperature difference is only 11 degrees and should be at least 20 +. He took the temp from the vents. Don't have all the info. Also no freon was needed.
We were told that the unit is on its way out and just can't keep up anymore. He said there is nothing he can do - it now needs to be replaced.
He raised the fan in the condenser as it was low and compared the air flow coming out of the condenser with our neighbor's a few steps away (he has the same unit) and found: air flow on ours was much lower.
I am getting another opinion this week. Can you give me any suggestion? Does it sound, at 12 years old, that it needs to be replaced? Could he have missed something?
Thanks so much,