I just installed a brand new 3 ton goodman Heat Pump system... when the ac turns on , I can here the reverse valve open and the compressor kick on , and here is the question.. The 7/8" copper freon line gets ice cold as it should but only for about 10 seconds and then it goes back to a normal but only slightly cold tempuerature.. and doesn't really blow out cold air.. We have tripple checked freon so not too much or little.. changed T-stat and this thing is driving us nuts... The only thing we haven't changed is the original coper line from outside to inside, though, I would think it isn't clogged... Any ideas?
Thanks
Jon

Did you flow nitrogen when you brazed in the new unit with number 15 silver braze alloy? Did you pull a dubble vacuum on the system with a good quality vacuum pump? Did you do the required super heat or subcooling calculation to actually charge the system? Did you take a amp draw to be sure the compressor is operating properly? Did you leak check the system? Did you hook up the new outside condenser on to the old coil? Did you ad a filter drier to the system?

These questions need to be answered for any further help. Also include the model number of the unit.

I just installed a brand new 3 ton goodman Heat Pump system....when the ac turns on , I can here the reverse valve open and the compressor kick on , and here is the question.. The 7/8" copper freon line gets ice cold as it should but only for about 10 seconds and then it goes back to a normal but only slightly cold tempuerature.. and doesnt really blow out cold air.. We have tripple checked freon so not too much or little.. changed T-stat and this thing is driving us nuts... The only thing we havent changed is the original coper line from outside to inside, though, I would think it isnt clogged...... Any ideas?
Thanks
Jon
You could try putting your guauges on the unit and start the system observe both the red and blue side of guages and see if when it is not as cold if there is a noticeable change in your readings if you get a dramatic change you probably have a clogged cap tube or tev valve.