I uploaded a picture of the Irritrol valve that I found 90% closed on the water flow out pipe. Colin tested the unit after cleaning the filter and it satisfied the thermostat. Customer says after the plumbers came the unit worked for a day before locking no out on low pressure. Given the mild temperatures the unit would not have been having to run much and with the valve 10% open it would take at least an hour of continuous run time or more to fault. It is possible it was closed by a plumber and not opened all the way. I called Colin to verify warranty status. Unit operating normal.