I have a GOETTL HP361F/H Heat Pump installed in my home in August 1984 before I moved in (36000 BTU Cooling capacity, EER=9.50/10.40, SEER =11.00/12.00). The Compressor was replaced in July 1997. I have a 2000 sq ft one story home in the phoenix, az area and I like my house cold (around 70 degrees at night/78 during the day). I have ceiling fans in all rooms, which I also have on at all times.
The unit used to keep my home very cold, but over the past few years, my home is not staying cool (even if I run the AC 24 hours a day instead of having my electronic wall thermostat turn it on/off). My unit is starting to get noisy (can hear it outside my house as well) ... didn't used to be. If I run it continuously, it just stops blowing air altogether although I can still hear it running. Sometimes it blows air which isn't cold (but not warm), but if I turn it off for a while, it seems to blow cold air again.
I've tried to have various A/C companies out to fix it, but they don't identify any problem (but I'm not sure if I'm really getting quality people out to work on it ... e.g., last person spent the whole time at my house off/on his cell phone).
So, I'm wondering ... is this unit worth trying to fix given that the unit is 12 years old and that I can't seem to find anyone to fix the unit so it works as well as it used to. This is my first house ... so I am wondering how long should a heat pump such as this last? The original warranty was only 5 years parts with 2 years labor so maybe this unit is at the end of its life.