Navien NR-240A Tankless Water Heater – Day 0 Results

I had a Navien NR-240A Tankless Water Heater installed three days ago (the install took two days).  After the installers left (around 5:00 PM), I had a bit of a scare — my wife was trying to rinse dishes in the sink, and she couldn’t get any hot water.  I let the water run — literally for minutes — and sure enough, the water was still cold.  I knew the installers had tested the unit before they left, so I thought I might not have enough flow to activate it (more on that later).  I turned on a second sink, and sure enough – hot water from both faucets.

The thing is — the “A” models from Navien include a built-in circulator to eliminate the minimum flow requirement that is apparently common with tankless units (as well as provide several other benefits) — so I should NOT have been having this kind of issue.

Turns out the Navien also has a thermostat of sorts which controls not only the target temperature but also the times (in half-hour increments) that the circulator should be in operation.  My installer had not activated the circulator.

So, after giving the manual quick scan, I was able to setup the circulator.  With three kids at home and it being winter, I decided to keep the circulator operating at all times, at least initially.  I plan on experimenting a bit and will share my results here.