Tankless Water Heaters?

Tenspound

I need to replace my water heater. I thinking about a tankless. What would be a good one? I'm just wondering if the benifts out way the cost of the unit.

ricks_plumbing

Rinnai is a good brand I have installed several and never had a problem just make make sure you have adequate gas supply pressure, I have never seen this as a problem but it is really the only variable that would prevent it from working correctly as long as you purchased the correct model for your water demand
As for the benefits you are able to set the temp on outlet and it is accurate within 2 degrees. This means you can turn on only the hot water in the shower not have to worry about scalding and never run out of hot water as for yearly cost they are more efficient because they arent trying to keep 50 gallons of water preheated constantly the heater just kicks on when you open a hot side faucet
Although you are correct about initial cost this particular brand has its own venting system (mount it on an outside wall and it shouldnt be to costly

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Rick McCarthy
Ricks Plumbing
OakRidge TN

Tenspound

Are the bosch Aqua Stars any good? I've only installed one tankless before at my buddy's house just before he moved it was a Bosch so I have no idea if it had any problems. It seems like they have good prices but that could mean that they aren't any good.

jproffer

Tankless W/H:

Pros:
- Water isn't heated and reheated when not used.
- Takes up less space in the basement/attic/closet/whatever
- No more "hot.....not so hot ......luke warm.......cool.......COLD " showers

Cons:
- Sediment that is in most water doesn't have a chance to settle out in the W/H tank, and therefore will continue on through the house and clog faucets, shower heads, etc.

All this is just my opinion of course as I haven't actually SEEN faucets after years of being fed by a tankless W/H, but I have seen the bottom of a tank that eroded all the way through, and the minerals/sediment/etc that caused that have to go SOMEWHERE.

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Jim P.

ricks_plumbing

biggest thing I would look for is the heaters flow rate capabilities can two showers run at one time or will the washer "steal" the hot water from my shower etc...

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Rick McCarthy
Ricks Plumbing
OakRidge TN

Neil_K

Will you share the approximate cost for the rinnai, installed/ replacing existing 50 gallon hw heater? Is there any maintenance on it? Just trying to get an idea.

Thanks.

Neil

747

http://www.rheem.com/tankless/

Rinnai is also a good tankless. But plan on spending more for it.

Atricaudatus

Neil,
I just installed two rinai's on a high end home here. No info the performance thus far, but the cost was right at a grand for each unit. Not including the installation.

I think there is some minor yearly maintenace recommended (flushing or something, but i don't recall for sure.) Nothing dramatic.

I plan to ask the HO, who recently moved in, how the units are doing.

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-Rhett
Licensed electrician and plumber

Neil_K

Thanks Rhett. Thats not too unreasonable for hot water. I'd imagine there's a bit of retrofitting in existing due to the line locations. Our 50-gallon gas just doesn't keep up. We've had Rheem replace parts but 2 showers and its shot. I'd pay the extra to keep my wife from complaining

oldgoat

What kind of venting do they require? I understand that they take a 8" vent.

ricks_plumbing

no, it's about 6" direct vent it does hve its own type of venting which does have some limitations but none that I think you would run into for residential application best is to mount it on an outside wall OR they do have a unit that mounts outside which doesent require a vent

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Rick McCarthy
Ricks Plumbing
OakRidge TN

Atricaudatus

I used the models that mount on the exterior of the structure and have a built in vent. So they require no additional vent piping and no make-up air as interior set ups do. The unit is totally self contained, with the exception of the shut off and TP valves. They also have a small remote control unit that mounts on the interior and takes a low voltage cable, like thermostat wire. The units I used also required 120 VAC to the unit, as well as a 3/4 " gas line.

The install was pretty simple, and I spoke with the HO last night and he reports that he couldn't be happier with the performance. He says he sets the digital t-stat to 115 degrees and its perfect, and he never runs out, even when filling his whirlpool tub.

These things are becoming pretty popular in these parts and are getting a lot of interest from HOs. I am told they've been in use in Europe for many years, so the technology isn't new.

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-Rhett
Licensed electrician and plumber

oldgoat

How do they have a outside water heater keep from freezing up in the winter time?

Atricaudatus

OG,
In this part of the country, winters are pretty temperate so it may be less of a threat than in many more northern climes. The 120VAC I mentioned is connected to the unit and powers an anti-freezing circuit that is supposed to cut in when the outside temp dips below a pre-set level. I didn't study the schematic very closely, but I presume it's some variant of the old heat tape concept. The exposed supply piping below the unit is insulated with 1" wall high density cellular foam.

I am sure Rinnai's website probably addresses this issue better.

Rinnai also offers a flush mount recessed enclosure for these units that encloses the unit and the piping. But it obviously takes a wall deeper than normal. I have installed two of these in a home with 6" outside walls, and we still had to fur the wall out inside another 3". It was a walk in closet so the HO didn't mind giving up the space in exchange for the sleek look on the exterior. The other unit we managed to position in the cavity behind the fireplace framing, so no addtional wall depth was needed.

Freezing pipes isn't something we generally worry about here in eastern NC.

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-Rhett
Licensed electrician and plumber

primo p

the big question is wether you want Electric or Gas. Gas tankless heaters are the wave of the future but electric types don't work.

Grumpy

It's interesting Primo brought up the electrinc tankless heaters. The condo I live in is all electric, NO GAS. I am about to start the bathroom remodel, and the tank is in the bathroom leaving me in a peculiar situation.

My first thought was to go tankless but I heard from some about a year or two ago that the electric aren't all that hot when used for showering. I like to take long hot loooong showers, after all it's the only time of day when I can relax.

What are your guys thoughts in general on the ELECTRIC tankless water heaters?

RobertF

I've installed a few of the Takagi tankless units and had no problems with them. Both the TK2 and TK1S were easy to install and haven't had any complaints about either of them. Both homes I did the water heater was in the garage and the tankless unit went right where the tank used to be. Biggest problem was upsizing the gas line as most only had 1/2" fed to them off of the 1" running the house.

The Takagi requires a stainless steel flu which wasn't particularly cheap.

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-Robert F

xoroniox

Had a tankless electric install in a small apt over a year ago, and no complaints thus far however, terribly easy to adjust the temp which saved me time because the home owner was able to turn it down by himself after calling me out, but anyway all in all i would not want an electric tankless installed in my house, just my 2cents

MSSI

What is the max Temp. setting on a tankless....If I dont run hot and cold water at he same time I get Crap for water flow..Right now I have my gas water heater set at max. so I can get a good shower with Hot cranked open all the way and Cold open between 3/4 to 7/8...

JamesNLA

"What is the max Temp. setting on a tankless....If I dont run hot and cold water at he same time I get Crap for water flow..Right now I have my gas water heater set at max. so I can get a good shower with Hot cranked open all the way and Cold open between 3/4 to 7/8..."

Max setting on a tankless will be around 170F. However it has that ability for other applications...not a a basic SFD. Mind you, anything over 125 and you can get 2nd degree burns. Homeowners don't like getting burned. I pre set all mine to 120 - 125.

The VOLUME of water that get's to your faussets will remain unchanged...unless, the geniues used Galvanized nipples, that have become rusted out, that MAY help a little once those are gone. Make sure you remove the air raider to help flush out the lines, and start with the tub to bleed the air out!

If you have a regulator, test it! Maybe go a little fat on it, to get the right pressure!
Good Luck!