This morning I was resolved to fix the hot water heater situation for good, and get at least one hot shower in before both Crystal and I are out of town for the week. (I am visiting a client in Boston, and then going to Pasadena for the SciPy 2009 conference, and Crystal is joining her family on vacation on the east coast.)
So, with the new-found knowledge from yesterday morning (from Reggie Patterson the plumber, via José), I went into the attic while Crystal turned on the shower to the full Hot position. Sure enough, after a few seconds of hot water, our brand-new Rinnai started beeping with an error code 11 and shut itself down. I waited for its internal fan to stop, then turned it off and on. Crystal repeated a few more seconds of hot water, before another round of beeps, flashing error code 11, and shutdown.
After repeating this cycle 6 times, the unit finally stayed on for several minutes. Crystal started taking a shower, reporting that the water was staying comfortable hot, so I put the cover back on the Rinnai. I guess it takes about 8 power cycles for the system to flush the air out of the gas line. I climbed over the tangled mess of HVAC ducts, gas lines, and power cables in the attic, and came back downstairs. Crystal finished her shower, got dressed, and yielded the shower to me.
I stepped into the shower, turned it on, and was greeted by a blast of lukewarm water that quickly faded to cold.
I grumbled, cursed, and stewed, and after quickly finishing my 6th cold shower of the week, I got dressed and stormed back into the attic. Much to my surprise, the Rinnai was not beeping, nor was it flashing any error codes. In fact, everything seemed just fine, except for the fact that it was not delivering hot water.
This is something that the plumbers will need to fix next week.