# Tankless Water Heater Questions...............



## WoodMann (Aug 16, 2008)

Don't know if this is the right place for this, but couldn't find anywhere better. I _hear_ good things about these units and it kind of makes sense sor me as I use waaaaay less than 41 gallons of water a day(as stated in ads), but prolly because I so d@mn cheap to pay to heat anything. My big reservation on these units is how much do they really eat; gas or electric- to heat the water instantaneously for say washing yer hands? Y'know- I'm still infatuated with my big idea of 4 solar collecters on the roof and a couple solar powered circulation pumps to the heat exchanger and retrofitting it to my 60 gallon water heater. Which brings up the next question- how long would water stay warm in a water heater like mine if it's not heated for a couple cloudy days.......................


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## TMonter (Aug 16, 2008)

If you have a working water heater it's pretty unlikely that you'll save money with a tankless within the first 10 years/ Also be aware they have some major issues with hard water crudding up the heat exchangers. In the right situation they can save a lot of money but be careful and do your research.

Anything more you can tell us about your installation?


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## WoodMann (Aug 16, 2008)

Yeah- thanks Monter. Just tossing it around in my head I'd guess the best polace to put one is the main bathroom; shower and sink. But also the subdivision where I live pipes out well water to the community, while mines not as hard as I have a sofener you can still see the minerals in the water via spashing on the mirror. My folks are on the same aquifer and they have no sofener and cleaning the shoer is a half a day job. My big issue with these tankless things is that they'd use a boatload of power/ gas as they hafta get the water hot instantly. I'm not really doing anything right nowbut just checkin' things out. I'm still h3llbent on my solar idea deep down, just that people tell me that tankless is the best thing since sliced bread................


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## TMonter (Aug 16, 2008)

I'll see about making up an excel spreadsheet that Webmaster can post to give you a good comparison between tankless and tank models. I did a lot of research when I replaced my water heater and I went with another tank model because the savings just wasn't there in my case.

I'll see about getting that together later today to help you out.


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## DiscoInferno (Aug 16, 2008)

WoodMann said:
			
		

> My big issue with these tankless things is that they'd use a boatload of power/ gas as they hafta get the water hot instantly.



It takes the same amount of energy to heat water no matter how long it takes to do so.  A tankless water heater simply uses more instantaneous power over a shorter time.  It uses less energy overall from not having to overcome heat loss from a big storage tank of hot water.

Plumber I had in for something else told me it would be about $3k to replace my existing WH with a tankless.  It's definitely not cost-efficient for me.


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## MrEd (Aug 16, 2008)

I think where the savings come in is that the only use energy when you are actually using hot water. A typical hot water tank use fuel to get it up to temp, and then the thing loses heat all day long (good ones lose it slowly). A on-demand tank has no "standby" losses, i.e. all the BTU's go into usable hot water, not heating water that may or may not get used.

I would be interested to hear from anyone that has one installed about how much it costs them per month to operate - especially propane which is what I would need to use, with a family size of 6.


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## drlbuilder (Aug 16, 2008)

Ihave a K-1 on demand water heater,three of us,wife and 16 year old take long showers,1.5 gals. per week of K-1. Don


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## TMonter (Aug 17, 2008)

I have a pretty reasonable spreadsheet prepared I'll see if I can get web to post it. It makes figuring out savings pretty easy but if you give me your power cost, your daily usage in gallons of hot water, and your well or city cold water temperature I can estimate it for you.


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## TMonter (Aug 17, 2008)

Here you go.

Basic for now but accurate enough to let you know approximate savings:

https://www.hearth.com/econtent/index.php/wiki/File:Water_Heater_Spreadsheet.xls/


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## kinsmanstoves (Aug 17, 2008)

We have a Bosch tankless water heater (LP) in our main bathroom.  It is great.  Been running for over two years now and love it.  Call me with any questions.

Eric
330-876-0200


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## WoodMann (Aug 17, 2008)

Wow- 3 grand to get this thing installed. Guess another vote has been cast for the solar collectors. Ya see- I can get the collectors for free, dad has 10 of'em in his garage and I help him out all the time with painting and what not. I also feel that I'm missing out on a sunny day as if there are BTU's floating everywhere for the taking. I just wanted to nail down the true cost of the tankless unit; install, power consumption etc to the solar setup. Granted, I'm gonna hafta punch some holes thru the roof for copper tubing now................


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## mikeathens (Aug 20, 2008)

I have a Bosch Aquastar 125 (LP).  My water source is a hand-dug well and cistern (switch depending on time of year).

My advice (from experience) is this:  If you have good, constant water pressure and good flow, these can be pretty good - like from a municipal source.  I, however, have a jet pump and pressure tank, and I use water-saving fixtures, so flow not only is low, but fluctuates depending on pressure.

What this means is I have to keep the temperature turned up to the max (very hot) and in the middle of a shower, if the pressure tank is at the low-end for pressure, I can experience a pretty uncomforatble cold water shock until the pressure comes back up.

Another draw back is the fact that these things are flow dependent.  If you are doing something requiring low flow of hot water (i.e. rinsing dishes, rinsing beer bottles, need just a trickle of hot water for any other reason), it will cut out and supply you with cold water.

Mine is 4 years old - maybe some improvements have been made to address these problems recently, but I would check.

Propane usage is approximately 250-gallons/year, mostly for hot water (we also have a propane stove/oven and very rarely run a propane radiant heater in the bathroom in the winter).  Family of four - me, wife, 3-year old, and 6-month old.

I would rather have an electric well-insulated tank.  Even better, a well insualted electric tank (i.e. Marathon) with solar collectors.  That way, the electric only acts as back-up when needed, and will (hopefully) run infrequently.


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## FatttFire (Aug 27, 2008)

I have a Bosch tankless, and I could be a sales man for those things.  Yes its alot of money, I put it in myself, and total it cost me $1000!  You have to do alot of research, you don't want to size it to small for your needs.  Thats the biggest complaint.  Most people got the size smaller, and they hate it, well thats b/c you got the small one and it can't keep up!  I live on well water, I have the worst iron you will ever see.  I have a filter, and softener, but still get some iron.  My propane usage has dropped so much, the tankless paid for itself in 1 year of propane.  

Downsides:  you have to have a 3/4 gas line running to it, that was a pain but did it, while in the shower you have to keep the hot on full, and crack the coldto a steam bath, but I am still getting a steam bath.  Now I have theose anti scold shower heads so I don't get blasted with cold water when someone else turns on the hot in another room, so I can't tell you about that.  Another downside and the last, when the power goes out it shuts off.  It has an exhaust fan that exhausts the hot air and the safety trips when the power goes out, so you have to hit a small switch once the power comes back on.

All in all I love it will have another when I build my new house!  Oh yeah I only use propane to heat, and heat water.  Since I use wood to heat and my new furnace I spent $7000 on, :sick:  only has run for 20 minutes since April of 2007, so the rest is used for HW!  I filled my propane tank in January of 2007 and haven't filled it up yet and yesterday it was at 85%  Paid for itself!

Jason


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## SE Iowa (Aug 28, 2008)

I have a Ranai tankless on NG.  Although wew do have a NG stovetop, our actual monthly gas usage is b/w $6-10 per month I have a wife and 3 kids although they are small (not teenagers yet).  Mine cost $900 plus a small amount for installation.  It is direct vented so could go thru your existing exhaust pipes.  Only one complaint: There is a slightly longer time to get hot water from the heater to the shower 3 stories above (an EXTRA 5-10 seconds).  Once we got used to that, life is good.  We love it and figure it the difference in cost (~$500) paid for itself in 1 to 2 years.


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## WoodMann (Aug 29, 2008)

Thanks Grower- I'm still thinking everything thru, I'm even looking at photovoltic stuff but seems pretty cost prohibitive.........


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## pdboilermaker (Aug 29, 2008)

Dont forget, keep your tankless receipt for a $300.00 tax credit to lower the initial cost of the tankless


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## rowerwet (Sep 7, 2008)

I put in a paloma tankless from home depot myself about two years ago when my hot water heater bit the dust. My wife did notice a savings on the propane bill, but the price jumped soon after that so now my bill comes out to a draw. I also have a gas stove and dryer, but my wife uses the clothes line during the sumer to save gas. 
     I like the remote thermostat on the paloma, my 6 yr old can take her showers without any worry of scalding because the thermostat keeps the water at 106 all the time, it also makes it very easy to run a bath for my 4yr old when you can turn the water on and not have to keep testing the temp, and when we wash the baby we set the water temp to 100 and don't have to worry about burning her, the only time we turn up the temp to 120 (max) is to do the dishes. And when my wife wants to have the washer fill faster she sets it to the hot/cold water setting and turns off the thermostat so the water heater doesn't come on. The thermostat is mounted in my bathroom within easy reach of the shower for quick temp increases (up to 110 only if the heater is firing). 
     I put the paloma in my basement where the old 40 gal tank powervent unit came out of to simplify plumbing as my kitchen is at the other end of the house. the paloma also has an internal freeze protection using an electric element and a burn through detector built in. in the end the paloma came out to about $850 with all the fittings needed to install it. A direct replacement tank heater was $699 for 40 gal and would have been more to go up to a 50 or 60 gal tank which I was planning on doing. 
    I am on municipal water so pressure is constant even if it is lower as I am on the end of the system. I sometimes get small temperature spikes (not burning hot) when the kitchen hot is turned on momentarily during a shower.


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