Reply To: thermar instant demand hot water heater problem

[Harold KestenholzParticipant]

Most likely, your accumulated heat exchanger dirt broke loose from a local hot spot and the high limit cut the pilot circuit. It is cleaning, flushing and resetting time. http://www.asapheat.com/myson/thermar/parts_srch_pm1000.asp
http://www.plumbingsupply.com/mysonpartsbreakdown.html