L message on display Rinnai 38k vented heater

[Garye5007]

Set the temp to 75 degrees display shows “L”, Manuel states burner is in low combustion mode. It’s in a cold room. Does anyone know how to get it high combustion mode? Manuel is no help.

 

[gthomas785]

Is the L showing on the right or left side of the display? If the room is below 60 degrees it will show the room temp as L. This is not the same as the low burner stage L.
If you set the temp to 75 the heater will automatically modulate the burner and fan until setpoint is reached, it will not tell you what stage the burner is on.
If you want, you can bump the temp up past 80, it will show H on the setpoint and stay on max burn forever without modulating.

 

[Garye5007]

Gthomas, thank you very much for the reply. The L is on the right and the temp in the room I imagine is below 60° so I guess that explains it. I was just testing the unit to make sure that it worked correctly before I install it in an apartment. Thank you again