This unit started out great and within a month turned horribly bad. First, it is prone – and I mean seriously prone – to getting clogged with creosote. The heat exchanging tubes are small in diameter, which allows for the creosote to build up quickly. Cleaning with the provided tools is next to impossible. Second, the customer service is just about non- existent. I called many times, looking for direction on why it wasn't working, and would get a short answer, usually amounting to gee, we've never heard that (even though there are a lot of reviews saying the same thing). At one point they sent me new bricks to expand the air opening, but with no directions on how to actually replace them. All in all, find something else. UPDATE – 1/23/15: The folks there, Warren especially, are nice enough, but that doesn't help heat the house. He read my earlier review and had someone from his company reach out to me to discuss my troubles with the unit. I spent some time describing my creosote issues with him, and of course I received the obligatory "we want you to be satisfied" conversation. They sent me some aluminum strips to help clean out the vertical tubes, after a short "back ordered" period, along with a new 1.5 inch brush. I'll say this, when the unit is clean it works well, but you would either have to 1) only burn kiln dried wood (the wood I am burning is over 2 yrs old and has been covered the whole time but still not "seasoned" enough since I still have horrible creosote problems) 2) clean it bi-weekly which is fairly time consuming; I clean it once every two weeks and it's always very full of tar-like creosote, or 3) burn way more tsp with it than I am, I guess. My temperaturess stay above 170 until it gets really cold, then it will start to fall into the mid 160's, more demand. I still have my oil furnace on and it kicks on to help meet the heating/hotwater demand, so I'm not using the GX10 exclusively. All of the things they have told me are or could be the causes, don't seem to be the case. After getting it really clean about 2 months ago, I sent them an email saying I needed my brush replaced. I didn't expect it to be for free, but I got an email back saying it would be sent right away. Two months later, and I sent another email and got an email reply back that I should have received it. Overall, the work behind keeping it clean really doesn't seem to be worth it for me. When I think of what I paid to purchase and install it, I really wish I would have found something else. There is one solution to this and frankly the only thing that would make me a satisfied customer (and if this happened I would publish another review saying so) and that is if Hawken Energy had one of their folks come out and clean and service my unit and show me exactly what I'm doing wrong. I have followed their suggestions and instructions and still I am having problems, and I know I'm not the only one. I would just like Hawken to stand by their product in deed, not just in word.