NCB-250/150H - setting changed all by itself

Jaythepoomer

I came home from a long weekend away to find my heat isnt working. Hot water works fine the unit heated up like normal the minute i turned the hot water on and it worked perfect as usual.

My thermostat was calling for heat when i came home but the Navien did not show it.

I rebooted my Navien and once it rebooted, I saw the heat call from my thermostat and the unit began to heat up like normal... except... i did not hear the zone valves open or the circulator pump come on.

As a test i manually opened the valves. nothing.

Once the unit hit the 180 degree limit it just sat there. Im not sure at what point this weekend the unit decided to turn off the call for heat on its own, but I didnt wait that long and tried to figure out what was going on before calling the plumber.

Long story short

The setting zone pump / zone valve had changed back to zone pump. -- all by itself! Unless there was a ghost plumber at my house while i was gone, how did this happen?

Has anyone had setting change on their Navien combi boiler by itself?

Once i changed the setting back to zone valve - presto my heat was back to normal. Hopefully that never happens again, of course now its going to be in the back of my mind anytime I go away, especially when temps are really cold