rinnai 431 wta

st heat

greetings
i have a 431 and the room temperature always seems high - often 76-82 degrees (whether the unit is on or off), when the room is more like 68-70. i've had to set the auto temp to high if i want the heater to go on at all, and when it does the room temp quickly goes to 80 or 82 at which time the unit shuts off again. the only way to get the room really warm is to set the unit on manual high. is this just the way it is with the thermistor located on the back of the unit? there are no error messages on diagnostic.
thanks in advance i would appreciate any help.
j

Jack

Temp issues

What are the dimensions of the space the heater is in. The 431 will fire from 8,200-16,700 btu and modulate both the burner and blower. I have seen this type situation before when the air hits an obstruction (wall/furniture) and rolls back to the unit cycling the unit off. Essentially the air cannot get into the room or the space it needs to heat. Try adjusting the directional louvers to direct the air into the space. You can push them to one side or the other with a screwdriver blade.