Wishful Thinking

2 gals. vinegar recirculated for 1 hour

When the temperature drops below 50°F--yes, we who were born in Hawaii are wimps--the worst appliance to go out may be the hot water heater. (One can get through a furnace failure by adding enough layers and blankets.)

Our 14-year-old tankless water heater flashed an unfamiliar message--error code 14--that meant that the thermal fuse had been triggered due to an overheated heat exchanger (HE). The problem was likely caused by scale build-up in the pipes.

I spent a moment being mad at myself for believing the plumber who told me three years ago that annual flushing with vinegar was unnecessary; Foster City didn't have hard water and we wouldn't have scale. Before I called a repairman to replace the thermal fuse (expensive) and/or the heat exchanger (very expensive), it couldn't hurt to flush the water heater.

Two hours later--et voilà!--there was no error code 14, the water heater fired up, and hot water poured from the spigot. We had lucked out. Maybe the thermal fuse was still intact. Maybe it was merely emitting a warning signal. (This is a textbook example of wishful thinking, dear reader.)

Three days later error code 14 came on and stayed on. No amount of flushing or rebooting would activate the water heater.

To be continued....