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View Full Version : Tankless Water Heat. Yay or Nay?



Sean Malone
10-03-07, 09:09 AM
looking at a single application tankless water heater solution for our spa tub. Wife empties the 50 gallon tank with every bath. So either a dedicated tank or a dedicated tankless. I've heard the tankless doesn't make very hot water. True?
Wife likes hot, hot, hot water (around 150).

Indy
10-03-07, 09:14 AM
Bored?

Sean Malone
10-03-07, 09:16 AM
Bored?

You can tell?:)

All projects are on hold due to all developer resources being pulled over to the web redesign deployment (that failed). Internet is my friend. :)

KLang
10-03-07, 09:24 AM
We've got two tankless in our new house. The seem to work fine so far. Hot water seems to get to the faucet faster then in our previous home with the other style of heater. Ours are set to 120 and seem plenty hot. Not sure how high you can turn them up, I'd have to look at the manual.

Edit:

Our units are from Rinnai. The web site says they can be turned up to 140.

Link (http://www.foreverhotwater.com/index.php)

Spicoli
10-03-07, 09:42 AM
I'm doing the uber-remodel addition to chez Spicoli and I must say that the tankless comes very highly recommended. Have a builder pal in Salida CO, and another in Charleston SC, and BOTH use nothing but the tankless systems in all their new construction, old construction, remodels, etc.

I'm not to that stage yet, but in about 2 months, I will be seriously shopping for one.

Where are you shopping?

Sean Malone
10-03-07, 10:28 AM
I'm doing the uber-remodel addition to chez Spicoli and I must say that the tankless comes very highly recommended. Have a builder pal in Salida CO, and another in Charleston SC, and BOTH use nothing but the tankless systems in all their new construction, old construction, remodels, etc.

I'm not to that stage yet, but in about 2 months, I will be seriously shopping for one.

Where are you shopping?

I've got tankless water heater connections in Phoenix and London. :gomer:

Seriously, I glanced at them at Lowes yesterday when I was buying a sprinkler head. They want $400 for a 'single application i.e. tub, shower, dishwasher etc' unit.

Spicoli
10-03-07, 10:51 AM
I've got tankless water heater connections in Phoenix and London. :gomer:

Seriously, I glanced at them at Lowes yesterday when I was buying a sprinkler head. They want $400 for a 'single application i.e. tub, shower, dishwasher etc' unit.

go big./ that's what i have been told. my lowes ain;t got dick on tankless.

Ankf00
10-03-07, 10:55 AM
in Dallas we put one in, ordered over teh internets, don't remember the brand, the water was super f'ing hot if we had the unit adjusted that way. the big pain was hooking up power to the unit, needed to upgrade the breaker

Wheel-Nut
10-03-07, 11:01 AM
I've always heard if your house wasn't built for a tankless heater your just wasting your time trying to retrofit. Any truth to that?

Sean Malone
10-03-07, 11:03 AM
in Dallas we put one in, ordered over teh internets, don't remember the brand, the water was super f'ing hot if we had the unit adjusted that way. the big pain was hooking up power to the unit, needed to upgrade the breaker

Noticeable increase/decrease in electricity usage?

Andrew Longman
10-03-07, 11:04 AM
In the NE most people heat with oil hot water systems. The boiler does double duty for heat and hot water. I added a hot water storage tank that cycles through the furnace. Super efficient and never ever run out of hot water.

KLang
10-03-07, 11:24 AM
I've always heard if your house wasn't built for a tankless heater your just wasting your time trying to retrofit. Any truth to that?

I don't see anything about ours that you couldn't retrofit into an existing house. Ours are gas and are vented through the roof but I assume a gas tank heater would vent similarly. The builder did insist we had to have a water softener for the tankless heaters.

Ankf00
10-03-07, 11:46 AM
Noticeable increase/decrease in electricity usage?

can't say, the previous heater was gas, but there was supposed to be a net energy savings when all was said and done. the other advantage being the savings in footprint (1000 sq ft house) since the old water heater was in a closet shoehorned into an already cramped kitchen.

I like the sound of Longman's regenerative system, wouldn't work as well back home b/c of how little a heater is used though, and you're in the south now...

G.
10-03-07, 11:54 AM
I looked into these casually about a year and a half ago. The only downside was the cost. It will take several (10+?) years to recoup the initial cost from the energy savings.

TL will be perfect for me, I presume. When my 5 yr. old tank craps out, my kids will be hitting the teens. No hot H2O runout will be key then.

If footprint, no runout, coolness >>> co$t, go tankless. But again, I'm going off of memory from 2 yrs ago prices.

IIRC, these's some good data from some .gov site, maybe EnergyStar or something.

Andrew Longman
10-03-07, 11:57 AM
I like the sound of Longman's regenerative system, wouldn't work as well back home b/c of how little a heater is used though, and you're in the south now...

No kidding. I'll burn about 750 gallons on oil this winter. Plus a cord of wood.

But my AC runs only a few days/weeks in the summer.;)

chop456
10-03-07, 12:25 PM
Have her sit in the dishwasher with a miner's helmet and a scrub brush. She gets her superheated bath and you get rid of your soap buildup issue. Two birds - one stone.

I should really be getting paid for this stuff.

[Edit]Oh yeah - 150F? She's not trying to remove skin, is she? A hot tub is usually around 105F.

Wheel-Nut
10-03-07, 12:35 PM
I don't see anything about ours that you couldn't retrofit into an existing house. Ours are gas and are vented through the roof but I assume a gas tank heater would vent similarly. The builder did insist we had to have a water softener for the tankless heaters.


I have heard it is a gas supply issue. I don't remember the exact numbers but your gas meter only allows 10 psi into the home. ?? I'll try and look it up.

KLang
10-03-07, 12:39 PM
I have heard it is a gas supply issue. I don't remember the exact numbers but your gas meter only allows 10 psi into the home. ?? I'll try and look it up.

No idea. If we have a 'special' gas meter I don't know about it.

G.
10-03-07, 12:42 PM
No idea. If we have a 'special' gas meter I don't know about it.It'll be tied into the electrical panel, on the short bus.

I'll go now.

Wheel-Nut
10-03-07, 12:57 PM
No idea. If we have a 'special' gas meter I don't know about it.

I don't think it would be a special meter, it would have a higher psi regulator.

nrc
10-03-07, 01:13 PM
It'll be tied into the electrical panel, on the short bus.

I'll go now.

220, 221 whatever it takes.

cameraman
10-03-07, 01:22 PM
Wife likes hot, hot, hot water (around 150). 150°F will cause second degree burns in very short order. A very hot, hot tub is running at 108. There is no way you need anything over 140°F and you would never do even that if you have kids in the house. If you are filling one of those huge bathtub/swimming pools then a tankless model rated for a high flow rate is the way to go. The 4 gallon per minute models cost more of course. Also remember that these things pull 18,000 watts so you need to have ample power to your house. The older models had scale problems, the newer higher end models are designed to minimize that problem but it will depend on how hard your water is.

Sean Malone
10-03-07, 01:33 PM
re: temp. I know the temp dial on the current water heater is not actual temp, when I was looking up troubleshooting on the dishwasher I found this...


Water temperature. To check water temperature, hold a meat thermometer under the hot water faucet for two minutes; if it doesn't register a minimum of 140 degrees F, turn up the temperature dial on your hot water heater.

with a decent quality meat thermometer I'm getting 120F at the kitchen sink. The dial on the tank is set at 145.

My sister-in-laws hot-tub is set at 105 and I can do about 20 minutes. The wife can do an hour.

Spicoli
10-03-07, 01:36 PM
I can do about 20 minutes. The wife can do an hour.

an hour? dayum. You a lucky man.

oddlycalm
10-03-07, 01:40 PM
I looked into these casually about a year and a half ago. The only downside was the cost. It will take several (10+?) years to recoup the initial cost from the energy savings. I looked into tankless for around for the house we just bought, then decided to go with another stone lined unit. We're downsizing so the runs are relatively short and the cost of a tankless was out of proportion to any savings or convenience.

We've used a stone lined tank for the last 15yrs and it's been cheap to run and 100% trouble free. They cost around 30% more but you'll never buy another unless you move to a different house.
Stone lined water heater
(http://oikos.com/esb/51/vaughn.html)

For new construction of mid to high end housing tankless is a no brainer as it allows distribution of the hot water into zones, allows adding modules for more capacity of future additions, and building in the necessary gas or electric supply on a new house costs next to nothing. You are also burying the cost of the tankless heaters in the relatively large price of a new house.
Tankless water heaters (http://www.designerplumbing.com/store/Point_Of_Use_Water_Heaters.html)

oc

Brickman
10-03-07, 01:55 PM
We've got two tankless in our new house. The seem to work fine so far. Hot water seems to get to the faucet faster then in our previous home with the other style of heater. Ours are set to 120 and seem plenty hot. Not sure how high you can turn them up, I'd have to look at the manual.

Edit:

Our units are from Rinnai. The web site says they can be turned up to 140.

Link (http://www.foreverhotwater.com/index.php)

I agree.

The key of course is to not just slap one in, it's very good, but they don't like to be called a water heater.

A must is using their stainless steel vents, nothing but theirs, or one will have trouble. Also run vinigar through it every couple of years.

It cut our gas bill in half.

But if I had to do it again I would go solar like my parents did 20 years ago.

JoeBob
01-06-13, 11:40 AM
So, it's been 5 years since this thread was updated. But, I'm about to enter the market!

What are thoughts today? My house doesn't have tankless today, but I was thinking of switching. Will it work well here in the tropical land of Minnesota?

Are there better options? I have a gas water heater now.

cameraman
01-06-13, 02:12 PM
They require a high temperature, high flow stainless steel vent so you will usually have to vent it horizontally.:D

They also require a higher than usual gas flow rate, we had to upgrade the gas meter and increase the diameter of the line from the meter into the house. That could have been due to the 80 year old line, might not be an issue on a newer house.

They also need to be flushed annually so they are not totally maintenance free.

They require a certain water flow rate to turn on. You can't get a very low flow of hot water, the unit will turn off or not turn on at all.

Other than that I think getting one was a very good idea.

KLang
01-07-13, 09:52 AM
Our two Rinnai units have been trouble free so far. As cameraman noted the lack of low pressure hot water can be irritating. I think it is .5 GPM required to turn on.




They also need to be flushed annually so they are not totally maintenance free.


I had a service guy out a couple years ago to do that and he told me with a water softener it isn't needed until the heater displayed the lime buildup warning.