Water Heaters

[MiniDave]

So, how far south are you going to go?  8.gif

[gr8kornholio]

So on water heater subject what's everyone's opinion on tankless?  We had an electric one in the last house and loved it. This house if we did one it'd be gas.

[MiniDave]

Pretty much all you see in Europe. I've never owned one but for a typical American household you'd need a pretty big one - since it has to supply showers, dishwasher, clothes washer etc.

[MPlayle]

A friend of mine here in San Antonio uses one in his home.  His is electric and not overly large (whole house and 2-3 persons).  They are sized according to need: whole house versus single sink, 1-2 persons versus 5-6 persons.

Gas vs. Electric: Gas ones heat faster. 

Both require a minimum flow rate to activate - if you turn on just a trickle of hot water, they may not come on.

Both may require having special plumbing for being able to run a circulation of cleaning solution - especially if you live in a hard water area (like running vinegar through your coffee pot to clean it).

[cstudep]

I mentioned the tankless earlier. My BIL the plumber says they are good to go these days. Gas if you can, the electric ones just are not anywhere near as efficient and do not seem to last as long.

Hard water is the big killer (but it also kills traditional water heaters as well) so a water softener is preferred if you have hard water, otherwise you may require multiple cleanings per year to keep one going well if you have real hard water. The cleaning process is pretty straight forward these days as well.

He just recently installed 4 fairly large ones in some sort of series/parallel setup at a local car wash, they are all linked together with CAT5 and communicate with each other. They keep track of how long they have run and cycle through which is the "main" one based on hours to keep them all at about the same usage. Pretty neat stuff really, they have come quite a long way since first coming on scene in the US, like Dave said they have been around for decades in Europe.

[gr8kornholio]

We had to backwash ours every month or so.  Really just had to go hit a button and it spewed a bunch of water out a pipe that was routed from it to the flower bed.

[tsumini]

We built my son's house in 2007 and installed a Rennai on demand. (Rennai at the time was the gold standard) We ran it off a propane tank. the gas service pipe had to be larger than for a normal WH  for the proper size WH. It was still good when we moved in 2018 longer than i expected. The cleaning cycle is new to me but sounds like a good idea. 
Our mistake was running recirculating hot water through the hot water line to  supply hot water immediately to the faucet. Just before we moved we had a leak in the copper supply pipe in the spare bathroom. House was built with plumbing in the slab with copper. Did consider PEX but was too new to take a chance. We replaced all the plumbing with PEX going overhead and down the walls. $10,000 repair job and lucky it wasn't more. Found out circulating hot water thru copper pipe will corrode the pipe very quickly. Originally in PEX thru the slab would not have been a problem. Live and learn.

[MPlayle]

The cleaning cycles in the tankless water heaters is mostly for hard water regions.  The calcium/limestone buildup clogs them faster if heating hard water versus soft water.

Most of Texas (especially the San Antonio area and hill country) is fed by limestone aquifers = very hard water.

Most lake/river reservoirs tend to be considered soft water.