Rinnai e110cn Low Output Temp

Rbcozeman

Hi. Couldn't find this anywhere. My Rinnai e110CN intermittently and now permanently acting like it's 40F outside. It seems to be stuck in efficient mode with water temp at 115-120F instead of 165F. It's about 8F outside. The result is temp dropping in house. It did this a few times and it corrected when I pressed boiler on/off button (off then back on). It doesn't return to full flame when I disconnect outside temp sensor either. Burner is firing - just not hard. Feels like it must be a sensor giving it bad info. Thoughts? Thx in advance.