I bought this heater to install in my 5th wheel RV, as an auxiliary heating system to supplement the propane furnace. This heater functions properly, and seems to produce the required amount of heat. If you have researched this type of heater, you already may know that these heaters produce some combustion noise, but this heater dies not appear to produce any more noise than more expensive units. I suspect all of these aftermarket heaters are basically the same. So far, my heater does not smoke on start up or shutdown, and did not produce any combustion soot after running at a reduced load. I am happy with the heater performance and supplied accessories and installation hardware. The heater gets four stars because no instructions are included in the package. If you watch some of the online videos about parking heaters, you can easily determine how to install one if these units, but figuring out the controller functions can be difficult. I finally found a like controller for sale on another site with controller function instructions.