Westinghouse WGRTNG150 tankless water heating issue

[tmfixit]

This post is both a problem presentation and the solution.  I post this because I don't find many post for these tankless water heaters so I hope this help somewhere along the line.  I found that over the last few days the temperature of the hot water has been decreasing to the point where there was no hot water at all.  An inspection of the unit showed no codes, the burner would not light in a consistent fashion or not at all and while the main fan was running there was a gurgling sound as if the pressurized air was flowing through some water.  In fact, that's exactly what was happening.  After some dismantling of the burner and checking for leaks I found nothing obvious.  Checked the water lines and ran the water through the unit with the gas and electric turned OFF.  There was no sound or sign of leakage.  The only thing left was the condensate line.  I disconnected the drain and found no problem.  The way the condensate drain is set up allows condensation to drain into a small collection area below a fairly large shroud below the main heat exchangers and once this collection bottle fills a bit it then overflows into the condensate drain.  I estimate the size of about a pint, maybe a bit more, for the two containers.  I'm guessing at the point these fill with condensation then it works its way up the exchangers until it gets to the burner/flame.  There is a large clean-out  next to the actual condensate drain secured be a spring clip and a plug.  When the plug was pulled a small amount of water drained.  But, when the blockage was removed from the shroud, almost a quart of water drained from the entire unit.  The blockage was just some slime that probably accumulated over the years and was thick enough to block the drain.  Condensate system cleaned and the problem solved.  Keep the condensate drain system clean.