Discovered a typical "suction-side" air leak that appears to be coming from the heater. It doesn't appear to be coming from the inlet or outlet unions, and water does not appear to be leaking from the unit as the filter runs. Haven't tried to run the unit since I discovered the leak, as I don't want to cause further damage. I have basic mechanical aptitude, but electrical and gas repair skills are not in my bag of tricks (though I did successfully replace the main circuit board). My wife doesn't want me to attempt a repair, but I would like to know what I can do to try to diagnose the problem or who I might contact...a plumber or electrician...I would like to check it myself out before I call someone.
Is there a safe way to remove the heater cowling and run the filter to get a view of the uniit's operation? Are there any typical areas to observe that might be the cause of the problem? Do I get out the socket set or call...somebody?