Same issue for us. We seems to only use hot water for a short period during the day. Get it all over with at once. Then it isn’t heating the water for the rest of the day with nobody home.
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The propane unit was a couple bucks more than the NG version, but you’re right about the fuel cost.
I still feel tankless is more of a space-savings convenience than a money-saving tool. A tank-style water heater is not heating the water all day, it only comes on when the internal thermostat dips down below the designated temperature, and modern tank water heaters are insulated extremely well. I would guess that when not using hot water, it only comes on to re-heat for a few minutes, every 30 - 60 minutes.
People also say that having unlimited hot water can and will promote using more hot water, which could negate the gas cost savings, as well as increase your water bill. Luckily, our water is cheaper than dirt here in upstate NY.
How many appliances/faucets can the tankless heater handle at once. Can two people shower at the same time? Can I run the dishwasher, laundry and shower at the same time?
I usually expect smarter questions from you…
It depends on the size of the tankless unit to handle whatever load you put on it.
The one in my house is sized correctly and I can run the washing machine + take a shower with no issues.
thats why they have different sizes…you size it based on the load.
fry i can take a look on my lunch and crunch some numbers here.
as for the comments on buildup in these units, thats typical of everything, not just the tankless water heaters. have you looked inside the piping of your house after just 10 years? shits disgusting especially if you live in an area with not so good water. when we’re designing buildings lately we have been putting in systems such as the oneflow on the water service before the heaters. seems to be a pretty nice setup. they make smaller units for residential applications.
So you spend an extra $1000 to save what, about, $5 a month? Who runs their dishwasher while showering? lol
I do. I usually do laundry and dishes when I get home and then take a shower. :gotme:
So don’t buy one if its not for you?
We already listed multiple reasons outside of cost savings
It is more of me just trying to figure out how much hot laundry and dishes you guys must do everyday. 
alright fry…
first of all, what size tank heater do you have in that house? i imagine pretty big being a single tank…
anywho, navien makes an npe series which uses a 1/2" gas line, HOWEVER. this is pretty important! depending on what you have coming into the house, you may not have enough gas coming in. the 1/2" inlet for the npe can actually suck the gas out of the line and starve other equipent down the line such as your furnace. you need to check the sizing of the gas coming in to make sure you will be ok.
with their 240 size units, during winter months, bringing water temp from 40 degrees to 120 degrees will get you 4.9 gpm of hot water. at 2.5gpm shower heads youre good for 2.4 heads, so if you decide to run the dishwasher and then have both showers going at once, you should be ok. you may notice a slug of milder water when the second turns on, but the heater will catch up and you wont run out of hot water. during the summer months when ground water is more around 55 degrees, youre looking at closer to 7gpm of hot water.
as for the time to get hot water compared to a tank setup, that is a return loop issue. unfortunately most houses have really poor or nothing for a return loop. but you shouldnt notice much of a difference gong from the tank to tankless in that aspect, but you wont have to worry about running out of hot water
if youre doing a concentric inlet/outlet youre looking at a 6" hole in the side of the wall. keep it away from windows.
It’s more like my time is valuable and I don’t have to plan showers or whatever around the ability to have enough hot water
Everything. I can shower, have the dishwasher going, washing machine on hot washing whites, and be the last of 3 to shower and it’s fine. And this is in winter too, not in summer to give you a false sense of power. If I wanted, I could also open up all my sinks and run the hot water just because while showering and it’d be fine. Also, I feel that my Navien actually works better the more I ask of it.
Oh the irony! Says the guy who buys an RS6, spends $2345823458947598 converting it to 6spd, when a 996 would be cheaper and mop the floor with it. I will say though, I was SO happy to see said car when I had to run to Autozone because API gave me the wrong part. I took it to 1000rpms and was on pins and needles.
So my hot water tank decided to start leaking. Guess its as good of a time as ever to bring this topic back up.
I’m sure there are new players in the game for tankless setups. Lets hear any new feedback as well as setup costs to get one installed.
For my setup, my gas hot water tank ties into the furnace piping to run up and out of the top of the garage. Also have the main panel like 5 feet away for any updated wiring that would be needed. So that aspect of it should make installation pretty easy. So what kind of out the door pricing should I be expecting for a good unit in the 180k btu range?
Or at least until the gas runs out.
Big change in BTUs I would recommend making sure your gas line has the capacity to support it as stated earlier.
Also a heat pump water heater will have the lowest lifetime cost…but only by a slim margin
Anyone know someone who services these, I have a Noritz.
My dad just had his Rinnai tankless water heater go bad. I believe the unit was well over 10 years old…
What went? The logic boards on some haves the caps pop and they replace even out of warranty
Depends where the water heater is located.
If you have a finished basement, then tankless makes sense, who wants 50 gallons of water dumping all over carpeting, etc.
For cost savings, still not work it.
I have a 10 year old gas water heater, 40 gallon, and we never run out of hot water. But we do use low flow shower heads, and there are only two people living here.
Most of the year I use less than 10CFM of natural gas per month anyways.
Im sure tankless units rot out as well, and that would be like leaving a facet on in your basement as well.