tankless water heaters

stoney15

New member
Hey guys, do any of you have an experience with tankless water heaters. I am building an old grainery into a house and looking at putting in a gas tankless water heater. Space is a hot commoditiy is the main reason, also looking for some energy savings. Do they work as advertised,provided what is needed, hold up, etccc..... Any info first hand info would be great. Thanks.

Stoney
 
I have a friend who has installed a few and is putting one in his own house. He says they work fine and you easily recoup the cost of them.
 
they work great. Where the problem comes in, is that the house must be wired for them or piped for them. They require a tremendous amout of supply whether it be electric or gas.
Be sure to check the requirements of the unit before you get to far with remodeling.
 

Have installed alot of them since the mid 90's. The best thing is as long as water and gas is supplied and unit is working properly you have unlimited hot water.

Problems I have seen.
First- Not much gain in fuel savings if any. I believe some of this is contributed to using more hot water than normal. You are not worrying about the next person having hot water or running out so we tend to use more.

Second- it needs a power supply. If you have a power outage NO hot water.

Third- It cost 3 times more to purchase and install than a standard 40 gal gas water heater.Standard gas water heater last 10 to 15 years so it would be 30 to 45 years before you were even on initial cost.

Fourth- they dont always last here is a pic of one from last Thursday already done for and is discontinued it is only 51/2 years old.I have replaced alot just like this.


100_9192.jpg



I will add Iam an old school plumber and it takes me awhile to warm up to change.I do like them in a commercial application where they are in a series and one goes out there is still hot water.I also live in the Southeast where humidity plays some part in condensation which ='s corrosion.
 
I have one at our cabin and the only problem I see is that if you are in the shower and turn off the hot water the delay when coming back on can be chilling. I think that they are great in this application as I don't have to drain a forty gallon tank when I leave in the colder months.
 
i disagree with guess
Where the problem comes in, is that the house must be wired for them or piped for them. They require a tremendous amout of supply whether it be electric or gas.

i installed a navian http://www.navienamerica.com/
back in march. my propane bill has been reduced by 2/3. it should pay for itself within 3 years. 98.5% effiency and it even uses a plastic vent pipe.
i had a 40 gallon tank with a recirculater loop. there is no comparison
down side, if the power goes out you have no hot water, but power consumption is only 200 watts, so i am thinking it will run on a computer type of power back-up.
my 2 cents.....

and imo, the ranai (sp?) is way over-rated
 
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I'm not saying they use a lot of energy. What I'm saying that when they are in use they need a large volumn of fuel wheteher it be gas or electric. The overall consumption is supposed to be better in the long run. However as stated by CCP most people uae far more hot water when they have them running their bills up anyway. I know all the females in my house would!
 
They also are not designed for very cold water coming into them. If your cold water is below 60 degrees, they probably won't keep up. They are useless here where winter cold water is about 40 degrees.

Jack
 
If you had a hot water tank with a recirculating pump then the tankless hot water heater would be a huge difference for you. Recirculating hot water throughout your house does give you almost instant hot water, but it comes at an increased cost becuase of all the heat loss in your piping as the water is recirculated.

And guess is correct, most do require a larger power supply than a typical tank type heater because of the large amount of btu's they have to transsfer to the water in a short period of time.

As was stated above the tankless also has a relatively set temperature rise (delta T). Therefore, your upper water temperature is really dictated by the incoming water temperature.

I looked at putting one in my house a few years ago up to the point I would have had to have some electrical work done to get the required power supply for the unit. My master bath is almost as far from the water heater as you can get so you have to wait for hot water to get there.
 
I've got a gas (propane) one and I would put in another in a heart beat. While you probably do use more hot water, with my 4 girls in the family, running out is NOT an option!!!
 
I don't get the extra power supply thing. I installed one in a house back in 89 and just used the 240volt power supply from the old electric water heater and it is still working today. I have, also, installed gas ones using the existing gas supply (natural gas) and they are still operating. have had no service calls or replacements yet.
these things have been in use in europe for years. I was first exposed to them in 1972 in germany where they had them in their army barracks.
we americans are just slow to accept change sometimes. I do not have one in my house.
 
the heaters made in the 80's were very different from those available today. I have taken out tons of the old style for one reason or the other. Personally I don't know enough about the workings of them to tell you the difference and hope I never have to learn!
 
Quote:these things have been in use in europe for years. I was first exposed to them in 1972 in germany where they had them in their army barracks.
we americans are just slow to accept change sometimes.

Tankless manufactures like to talk about how they have been used in Europe for so long but they don't talk about how differently we live and build. Smaller homes, tankless units are installed in the bathroom, temps set on those units are set so that when they take a shower they just turn the hot valve all the way on and no cold is used. Lower temps set on tankless substantially increase their life span. It is a whole different game.

Quote:They also are not designed for very cold water coming into them. If your cold water is below 60 degrees, they probably won't keep up. They are useless here where winter cold water is about 40 degrees.


Jack you are correct! All of the tables I've seen will give you a temp degree rise & gpm produced at that rise. But they will not give you the lines' shallow burial depth can make incoming water be around 50 degrees or even lower. To put that in perspective, some tankless units that are rated for 2 to 3 bathrooms at 199,999 btu's would only give you around 4.3 gpm at the winter temperature of incoming water at each installation that you're going to encounter. Some water required 77 degrees rise. That's less than 2 flow restricted shower heads.

Tankless water heaters normally dont go trouble free/ maintenance free for 10 years.The COST it takes to repair these units when they fail, control modules and flow switches, compartment etc. Is usually 3 times the cost of a tank type repair.

Consumer reports agrees They don't recommend it as an investment the unit will need to be replaced before you recoup the cost in energy savings. Conceptually it is a good idea.

Consumer Reports

Iam thinking tankless will go the way of solar domestic water heating of the 70's. when the tax credits go south, the heater will also go south.
 
I lived in the Netherlands for a while, in a dutch house with a tankless heater. It was great, hot water forever. It was a small unit with a pilot light. If my water heater here went out and I had natural gas I would go tankless. The Dutch are pretty conserveative, if it cost a lot to use the Dutch would not use them, some Dutch would not even leave the pilot light on.
 
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