Welcome! Here are the website rules, as well as some tips for using this forum.
If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
Rinnai Boiler Excessive Fuel Consumption Problem
I am building a new house and installed Rinnai Q85SP on demand boiler for in-floor radiant heating and RC80i on demand water heater for domestic use. We started using them in October with a full tank. Our house size is 2000 sqft, plus garage and work shop1000 sqft. 40 days later the first bill came, it showed over 300 gallon use. It was only for the house heating. The house was under construction status but had been spray foamed (2 to 3 inches -R13) before we started heating with the unit. I know R-13 is light insulation but under construction using 5 small ceramic heaters we were only paying just over $400 to heat the place to 60 degrees.
During Christmas the temp dropped to single digits (5-9 above) and the unit stopped working and the house temp dropped, the service tech has no idea why it stopped working. Is this common?
At the end of December they filled the tank again and it needed another 300+ gallons to fill it again and just before Christmas we had R-55 in the attic. Twelve days latter the fuel usage was 2.3 gal per day, another twelve days later it used just under 5 gal per day and the outside temp was in the 30's for that period.
The dealer has no idea what is going on and we have great concerns overt this.
Any ideas what the problem might be? Could it be the size of the unit or a bad unit?
Your insight would be greatly appreciated.