I bought the pump for my OWB. I have 140' of 1" pipe. The pump has to push 280' and through a heat exchanger. It does a good job. Much better than the 007 it replaced. I would have given it 5 stars except I feel it's much louder than the 007. No problem in a OWB but attached to your furnace it could be noticeable depending on its location. We'll see how it does over the long haul.