I posted previously [nearly two months ago] about sediment and brackish water problems with our MT 540 Instant Hot water dispenser. Mountain Plumbing states that they are aware of these problems and state that they will replace the entire unit [not the hot water tank - just the faucet], although we still need to pay a plumber to remove the old one and install the new one. It is a huge annoyance and I am bereft without my hot water faucet. Sniff, sniff. Problem is: The finish is polished nickel and they are having problems getting the PN finish. Who knows WHEN I will get a new faucet. So just a forewarning to those thinking of purchasing a Mt. Plumbing instant hot or hot and cold dispenser: Make sure it is from new and recent stock - no older than six months old. If your distributor has had it longer than six months, you run the risk of having this problem somewhere down the road.