Although the instruction manual can be a challenge, there are plenty of videos available online to aid in assembly and operation. After assembly and filling the tank with diesel, the heater was fully operational within about 10 minutes. There is a slight diesel smell in the beginning but once the heater has fired up it goes away. I like the heater so much that I bought a second one. I recommend this heater to anyone looking for a quality built and inexpensive source of warmth.