Hot water at the tap with Home Assistant
What local control of our Navien unlocked: scheduled recirculation, an all-night override and a hot-water prime for the washer.
Hot and warm water instantly at the fixture, when we want it, without paying for recirculation all night. That’s what local control of our Navien actually unlocked for us. The first post covered the hardware: an ESP32 on the NaviLink port, the ESPHome integration, and about $30-40 in parts. ESPHome adoption gave us 37 entities to work with.
Scheduled recirculation
The community repo ships a Home Assistant blueprint for scheduling when recirculation runs. We set a schedule helper for 06:00 to 22:00 and left it alone. No recirculation overnight, no burning propane while everyone is asleep. We use presence sensors too, so if we’re not home, it’s not spinning cycles.
The history shows the heater cycles for about 2 minutes, roughly every 30 minutes inside that window. Not a constant burn - the NaviCirc valve under the kitchen sink opens, water loops, and the heater fires just long enough to keep the lines warm.
The NaviCirc is a temperature-activated valve that uses the existing hot and cold lines - no dedicated return pipe. The loop is simple: heater pushes hot water out, it runs through the hot line past every fixture, hits the NaviCirc, crosses over to the cold line, and returns to the heater.
The all-night override
We have a tile on the dashboard that overrides the schedule and holds recirculation on all night. The override can be for anything, but for us instant hot water for baby bottle warming has been great. Walk to the kitchen at 2-3 AM for a baby bottle warm-up, turn on the tap, hot water is there.
Hot-water prime for the washer
This one is the nerdiest and maybe the most useful.
Our LG washer and dryer are connected to Home Assistant, so we know when they come on. When a wash starts, the automation presses the Hot Button once to prime the hot line so the first fill is actually hot, then holds recirculation off so rinses stay cold. On the first real wash the outlet climbed from 114.8 to 125.6 F before the first fill.
Propane
Propane usage has been very minimal for us to be honest, maybe $20 extra since the recirculation went in. Insulated pipes have helped too. The heater is about a third of what leaves the tank, so tracking it precisely takes a little math. I did hit one bad 0 reading from the heater’s gas counter that double-counted the lifetime total until an availability guard on the sensor fixed it, but that was a one-time fix.
What’s next
We plan to install a second NaviCirc at the 2nd-floor guest bathroom.