I moved into a brand new house recently that has a Goodman heat pump. I'm sorry I don't have the model number with me now, but it is a 3 ton unit, scroll compressor, R22, 1800sf house. It also says it is charged with 188oz of refrigerant, enough for 15' of line. The low/high pressures are listed as 150/300 psi. The unit is running, but the termperature differential between intake and vent is only 12 to 15 degrees. If I set a temperature and leave it alone it can hold that temp, but in the heat of the day it runs almost continuously. I've seen it take two hours to bring the house down 2 degrees in the evening. It didn't heat worth a damn back in March when I moved in either. I've had the installer out to check it and he says the freon level is correct and he can't find a problem. He checked the ductwork to see if there was anything wrong and said it all looked fine. I've called him three times since then and have yet to hear back from him.
In the mean time I have a 6,000 btu window unit that seems to be doing a better job of cooling the house than the central unit. This just really sounds like low freon to me. The line run looks like it could be 30' and I'm thinking they just hooked everything up and didn't check it out (during the home inspection the unit didn't work - someone had shorted out a wire with a nail. That's now fixed but how could they have checked it out?) I want to check it myself but those pressure readings look awfully high. I don't know anything about heat pumps though - do they seem correct? What else could be causing this? I really want them to fix this because it's under warranty but I'm not sure they know what they are doing.