This weekend I corrected a plumbing mistake that was made when my trailer was replumbed by the PO. The city water line was connected to the hot water line by mistake. Since I camp and use water from the tank it was not a big deal. If I was on city water the hot and cold would be reversed. My trailer is plumbed with Pex with Flair-It fittings. These things are extreamly difficult to get apart. The fitting I thought I would just pull apart, I had to cut out. BTW, a PVC pipe cutter works great for this. Even with heat from my wife's hair dryer drier did not help get them apart. Soaking in hot water worked well, but that was not on option while I was crawled under the bathroom sink. The picture shows the finished (and tested) pipes. The splice on the right had a T originally and the T to the city water was added. The new pieces were ordered from http://www.pexconnection.com
, they have a great selection!