Check where you monkeyed around with the duct work. If it worked before it is probably something you've inadvertantly done. Also, there are two sleeves in insulated duct work. I had a cust. do the same thing you're talking about. The insulation at the connection slipped into the duct and blocked off his return to the a/c.
Originally posted by dbooksta
I had an attic space finished, and part of it involved routing existing 4" insulated flex-duct from the first-floor vent fans over and around joists. Now the fans appear to be fully obstructed.
Is there any trick to finding how far into a 25-foot run of flex-duct is an obstruction? Nobody I talked to had any ideas but there must be something better than ripping up floors and drywalls to expose the whole run?