3service calls in a month, $700 later & still not working?!? Not worth savings on gas which hasn't made much difference. Waited 3weeks w/o hot water for a pump. Unit ran 2days after indie service tech replaced another pump which he had already replaced April 6th. Obviously faulty product with a safety recall since Nov/14 & no one contacted me with any hazard warning. Unit broke down 14 months after installation, honor ur 12yr heatxchange waranty & replace this overpriced landfill anchor.