First I have to note my bias. I represented Rinnai for 20+ years and still consult with them. That said, I do heat my own home with them. Look at a Rinnai Energysaver. They are head and shoulders above any other DV heater technology wise. Modulating gas valve and house blower, Cool to the touch, seven day programmable t-stat built in. They also have a simple function lock. My 16 mo old grandson loves to play with the heater. It being cool to the touch and the function lock he isn't turning off, up or down the heater. How big a space are you looking at heating? What kind of heater did you put in?www.rinnai.us

Jackfr
Room is only about 12 x 12 and the direct vent natural gas heater does the job 90% of the time. Only want a heater that will supplement my gas heater and add a little extra heat when needed. Thanks for your reply and I certainly will take a close look at the Rinnai's. Paul

Got it! If you were to look at a Rinnai for that size space you would use an EX08. It will fire from 3-8kbtu. Good luck with your project.