Originally Posted by oh'mike
The reason that you pay the big bucks to blow out the system is that you need a BIG compressor--the kind that tows behind a truck--I don't know the size--but it takes a lot of CFMs to clear those lines.
I know a lot of people say that it takes a lot of CFM's but I've done it many times with just a small compressor with the 2 gallon tank and never have had any problems. I only open the valve to one zone at a time so I don't try to blow up every zone at once. I'm sure I don't get the system as dry as they do with the big compressors but it works.