Under the heading of "Better Late Than Never"... I wanted to close out this thread that I started. The winterizing problem was traced to the manual valve that is labled "Normal or Bypass". The valve itself was not closing all the way, allowing pink stuff into the water heater. I had feared that it was one or both of the one way check valves going into the water heater. Very glad that was not the case since the only way I can find access to those check valves is by removing the water heater. Regards