Thompson plumbing reversed hot and cold service valves on EZ TR40 tankless water heater. Thompson plumbing glued condensation drain as well. Turned water back on. Plugged water heater back in. Ran water to test for proper functions. No leaks found. Water heater works good for now. Thompson plumbing recommended flushing water heater. Customer already has someone scheduled to flush heater. No charge work under warranty.