atmos in garage

i recently installed Atmos stove in my garage (1 car), i am in Mass and bld inspector won't submit permit if system is pressurized so i installed a open pipe looped off the 30 gal tank expansion . Now its an open system. My heat/water storage is a 500 gal propane tank(still smells). Next requirement is to narrow the garage door opening as per Inspectors request. I might just cement in a 4 foot column to keep all those cars away! Any one having to deal with small towns in Mass (I live in Hampden 01036), ? I am anticipating a problem since the stove has only European testing.
Robb Wallace

Hi Randy,
I have a Atmos DC25S . there is a mixer in place for returning water (ESBE thermostatic bypass valve) and i plan to add a corrosion inhibibitor p/n 165 to the water. i believe i'll need a test kit . The square plated heat exchanger is mounted on the basement wall next to the oil fired furnace (Utica Boiler 117000 btu ) and there are two pumps in the flow system. Tks Robb