Came out to call for a system not heating properly. Customer stated that it will run for a little bit, then it will shut off and never maintain temperature. Customer had an issue a couple years back with the condensation line freezing up. Checked system over and found the line frozen up again and the units drain backing up and causing a pressure switch issue. Customer had ran heat tape halfway down the line, but not the rest of it and it froze there. Part of the pipe was cracked, so I had to replace part of the line. Then I ran customers supplied heat tape the remainder of the line and reinsulated the pvc line. Cycled system on and unit reached set temp by the time I was done cleaning up. System is now heating properly.