Bill: Tankless water heaters are fairly common where I live, in South Carolina. New houses generally opt for these when building. They cost a little more to install so some people say "pass". I am not familiar with the brand you named but depending where you live, if the winter temperatures go below freezing, get a water heater that ensures the exterior tank/pipes don't freeze. This is generally done with a factor= y installed electrical heater that, should the unit get to the freeze point, it just keeps it from freezing. You didn't say if you had gas, natural or propane, but here, they are natural gas. Also, talk with your plumber to ensure placement of the unit is central to all of your piping; i.e., there are some pipe length considerations/limits for tankless hot water and if you have long lengths o= f pipe, you may find that you may need 2 units in different places in the house to properly meet your expectations. They work well, are very reliable. As a summary, for a retrofit, you'll hav= e gas, electrical, plumbing, exterior siding work so it isn't cheap to get this done.=20 I hope this helps in your consideration of this project. Rich -----Original Message----- From: piclist-bounces@mit.edu [mailto:piclist-bounces@mit.edu] On Behalf Of William Couture Sent: Friday, May 06, 2011 10:28 AM To: Microcontroller discussion list - Public. Subject: [OT] tankless hot water heaters? Hi all, My wife has decided that we should get a tankless hot water heater to save energy. They are fairly uncommon in the USA, but fairly common in the rest of the world. Does anyone on the list have any experiences they could share with me? We are looking at the Navien CR-180A (this one includes a small, 1 gallon holding tank as a buffer) and the Noritz NR83-DVC. Any personal experience with either of these? Also, the Noritz is a new model. If you have experience with an older model that would also be helpful. Thanks! Bill --=20 Psst...=A0 Hey, you... Buddy...=A0 Want a kitten?=A0 straycatblues.petfinde= r.org --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .