Tankless water heater

[Jim Perry]

I am nearing completion of an auto shop for myself and wish to have hot water at a sink, so I am looking for something less than a "whole house" electrical unit.

Can anyone make suggestions? I have seen a Tempura and also noted that Rinnani gets good reviews within thsi forum.

Thanks,

jim

 

[bob15]

I have a Rinnani for my house hot water. I've had it 4 or 5 years now and love it. i have the LP version. Make sure you spec it for big enough for any future expansion (even if you're not looking for the "whole house" right now).


bob

 

[olytdi]

So does this need to be electric? I have a NG Bosch AquaStar for my house and it's been flawless going on 8 years now. Did the "once a year" rebuild kit about three years ago and it's awesome. Halved my NG monthly bill.

 

[Jim Perry]

"Does it need to be electric?" No, but it would be so much more simple if it were. This is not a daily use application, and unless I get kicked out of the house, I am not intending to live in the shop space (which is about 200 feet from my house) so I won't be needing it for a shower and a hot tub and a dishwasher. Only a little ol' sink.

(I have an on-demand propane heater in my northern WI cabin and am happy with it, but that's really a whole building application.)

Jim

 

[Charles (in GA)]

It hinges on the amount of power you have available in the garage and how cold the incoming water is.

I was looking at a Rheem instant water heater, and for the potential of 3-4 gpm and given a incoming temp of about 50F and a final temp of about 110F, I figured I would need a 28,000 watt unit, which requires a 60 amp circuit. I could get this one for about $200. For the time being, I think I'll stick with my 2 gal tank type under the sink. It gives me enough hot water to wash my hands, face, etc., and using the Kill-A-Watt, I determined it uses about $4 worth of power in a month in the winter. In the summer, I turn the water heater off.

Charles

 

[1965gp]

Look at a point of use water heater like one made by eemax. If you only need the water at the sink this is a cheap option.

 

[rwhite692]

I have one (Stiebel-Eltron, point-of-use) in my shop supplying a utility sink and a bathroom sink.

Love it.

It uses a 220V/50A circuit. It is completely hidden under/inside the bathroom vanity sink cabinet.

Provides plenty of HOT water, I use it to fill 5-gallon pails of hot water when washing the cars.

The H2O heater is a Stiebel-Eltron DHC-E 10. I got it from this place:

http://www.e-tankless.com/stiebel-el...0-tankless.php

I also installed a small inline scale filter (Cuno Aqua-Pure AP430SS) before the heater, as it was recommended by the folks I bought it from, to maximize life of the heater...and was not much money.

 

[mrobins297aaa]

Here's what I have for hot water in my barn, its a ecco temp and it works ok.

 

[70redbee]

Here's what I have for hot water in my barn, its a ecco temp and it works ok.

Why did you place the sink so far away from all the plumbing?

 

[lotsoftools]

I have an Ariston 4 gallon, 120v water heater in my shop apartment. It gives plenty of hot water at the sink and even enough hot water for a good 5 minute shower.
Got it at Lowes or Home Depot, can't remember which.

 

[barks]

Go to Lowes or HD. Trade $120-$150 for an under counter, 110v plug-in hot water heater. Install under sink. Don't overthink. Move on to next project.

 

[ehaines]

I agree with lotsoftools and barks. When I design little tenant finishout projects with remote sinks in the warehouse I like to go with 120V 6 gallon water heaters as opposed to Chronomite instantaneous water heaters. They are cheaper, require less power/wire size and are plenty big to serve a hand wash sink or mop sink. If you need more water than that take a look at the Takagi/AO smith line of on-demand water heaters. The one I have on my house has been great for 5 years.

 

[texmln]

I installed a Bosch AE 125 electric in my barn to serve a bathroom with a shower and a kitchenette. I read quite a bit about them before I bought it and they did not have a good reputation when originally sold. I ended up buying a refrubished model from a Bosch refurb site after reading the refurbs totally replaced the failing parts in the original models with newly designed innards that were much more reliable. I've got three years on it and it stills works great with untreated well water right out of the ground.

 

[rwhite692]

120 volt six gallon H20 heaters are great, if you are using hot water on a daily / hourly basis.

My Shop is only being used by me on some weeknights, and the weekends.

Do I want a 120V/6 gallon water heater sitting there, keeping six gallons of water hot, all the time?

Hell No!

Not with electricity costs the way they are these days. Especially here in northern CA.

If your usage is infrequent / intermittent, Tankless point-of-use, all the way!

 

[Eagle Point]

I bought the Ariston 4 gallon at Home Depot and installed it under the sink in my detached garage. It worked great for washing hands and basic clean up. I think it may need a 20A circuit? Clean and simple if it is just for a sink in the garage.

 

[bora492]

Jim and RWhite,

What about a 6-gallon heater with a weekly timer? Look up the Intermatic 601571 electronic heater timer. Shut if off during the week, and only turn it on during the weekends.

Dave

 

[rwhite692]

Jim and RWhite,

What about a 6-gallon heater with a weekly timer? Look up the Intermatic 601571 electronic heater timer. Shut if off during the week, and only turn it on during the weekends.

Dave

I suppose that would work. But it will still be on, all weekend long.

A point-of-use tankless uses no energy whatsoever, unless water is flowing, and it costs only about $80 more, than a typical 6-gallon water heater does.

It is also more compact and will put out more hot water than a 6-gallon, which will not keep up with a constant flow, as a tankless will.

 

[Jagmandave]

Is the shop heated in the winter? If not, you'll need to provide a way to drain the water heater so it doesn't freeze.

I think one of those 120V under sink on-demand electric heaters would be perfect for this, makes plumbing a lot easier too as you only need to run one line to the sink - the cold.

 

[911mike]

I also have a 4 gallon ariston heater. It works great for small use like washing hands and about a 5 gallon bucket warm water to wash the cars or mop the floor. I ran a usage meter for a month and it cost about $20.00 a month to use. Now I just turn it on when I'm out in the shop mainly the weekend and dropped it to $8.00 a month. Just a FYI

 

[woody9]

i had 10 or 15 gallon down in my shop that i usually turned off in the winter months as it was just to expensive to run (elec). Shop has 1/2 bath & sink in the bays. Went to a 2-gall/on-demand from one of the box stores and leave it on all the time.
Plenty to wash your hands after a project.. or maybe a bucket of hot suds for the floor and gentle enough on power use.
Had them plumbed in where if it need a TON of water, both can operate.
Both are 110 heaters..
can dig up the brand if you're interested..

 

[Jim Perry]

Really appreciate all the information. I went to Menards today and found that they have units that apparently have to be direct wired. Not an issue, but I thought a 120V unit could be plugged into a GFI outlet. Interstingly, the 120V is a "special order" while the 240V are in stock. The smallest one was about $180 I believe.

The shop will not be heated all the time (Wisconsin) and the lines can be drained. I have installed a frost free hydrant though the concrete floor; that will be the cold water source.

Anything that is said to have an "X gallon" capacity sounds like a tank to me, and combining that with "on-demand" seems counter-intuitive. I must be missing something.

Brand names/sources appreicated.

 

[Bear]

So here is what I have - it is an Ariston tankless 120V unit that provides all I need for hand washing etc. in the shop (which is not a lot). The only consideration is the chanch of freezing. This past winter I during the freezing weather I put a light bulb in the cabinet to keep it warm. (or I could drain it for extened periods) Of course I live in western OR where we don't have a lot of extended deep freezing.

 

[Chaz]

I have 3 Rinnai's - 2 in rentals, one in my former home. I've had some trouble with "cold water sandwiches" My supplier suggested I try a Navien in my new home. I love everything about this unit! A far better buy. Quieter, more reliable, and no cws

 

[mrobins297aaa]

Why did you place the sink so far away from all the plumbing?

I didn't want it in front of the heater and next to it I have all my communications wires that enter the building that I may need to get at that electrical box..........so thats where it ended up.

 

[CamarosRus]

Opened this old thread in hope of acquiring education on the subject.

I'm wanting typical (??) shop hot water for misc laundry tub chores and car wash bucket..PLUS wanting shower water as I'm considering adding a neo angle corner shower.

Shower would not be regularly used at this point but I need to decide if I should keep (what size ?) regular tank heated or install ?? tankless set up.

I can do install myself so expensive install labor isnt a factor

Please give me brands and model # if possible

 

[Jim Perry]

While I have yet to do any hot water in my shop, based upon experience at my northern WI cabin with a good sized tankless propane water heater I would say that is the BEST choice. I did the installation myself, including a power vent because it goes horizontally once in the attic. One never runs out of hot water, and you're not heating water that is getting cold while not in use. You can't let the system freeze -- I drain pipes and keep heat at 54F when not there, with an alarm in case power goes out.

In my shop I have water coming in via a frost-free hydrant (the valve is about 5 feet below grade). I don't know if I will keep the 40x55 insulated shop from freezing -- I doubt it, so whatever hot water system I install I will need to be able to blow out pipes. But I am not going to make it easy for my wife to say "You're outa here" by installing a shower to go along with my [powder coating] stove. No toilet either, but I'm out in the country!

 

[cj7365]

I have 3 Rinnai's - 2 in rentals, one in my former home. I've had some trouble with "cold water sandwiches" My supplier suggested I try a Navien in my new home. I love everything about this unit! A far better buy. Quieter, more reliable, and no cws

What is a "cold water sandwich" I have a Rinnai and has performed flawlessly

 

[bgarrett]

I use a Coleman propane on demand heater. I think they say is is for camping and cost about $200. Excellent unit. I added a valve under it so it doesnt hold water that can freeze and burst it

 

[Angelfire]

Why did you place the sink so far away from all the plumbing?

So he could get it closer to all the power cords!

 

[Oldbear]

There are great "under-sink" electric on-demand water heaters; built just for a sink or two. A popular option for sinks away from the main water tank. I have seen them for around $200 a local lumber yards.

Good hunting.

 

[Voodoo Chili]

We just moved into a home that has a tankless water heater.. It's about 10 years old, but ours takes 5+ minutes to warm up. i understand it takes time to get the old cold water out of the pipes and warm coming out of the spigot, but this is twice as long as any house I have ever owned before.. It's okay if you plan for it... Turn the shower on, go use the throne, and come back, but seems like a waste of water to me... Maybe it's an old unit, and showing it's age, but most of the manufacturer specs say it should be good for 20 years... YMMV...

Go with whatever makes you happy.. Nothing in life is perfect!

 

[trackwelder]

We just moved into a home that has a tankless water heater.. It's about 10 years old, but ours takes 5+ minutes to warm up. i understand it takes time to get the old cold water out of the pipes and warm coming out of the spigot, but this is twice as long as any house I have ever owned before.. It's okay if you plan for it... Turn the shower on, go use the throne, and come back, but seems like a waste of water to me... Maybe it's an old unit, and showing it's age, but most of the manufacturer specs say it should be good for 20 years... YMMV...

Go with whatever makes you happy.. Nothing in life is perfect!

Tankless water heaters require yearly maintenance. I flush the scale out of mine every spring using a 3/4 horse submersable pump in a 5 gallon pail filled with vinegar.

Does your heater have the bypass valves installed?

 

[rrangus]

What is a "cold water sandwich" I have a Rinnai and has performed flawlessly

It occasionally happens. Also you need to clean the flow sensor screen ever so often. Don't ask me how I know about that. Hot shower this AM turned into a very cold one

 

[Jackfre]

What is a "cold water sandwich" I have a Rinnai and has performed flawlessly

Cold water sandwich is the cold water flow through the unit on start up. Let's say you were running a hot water faucet. You then turn the faucet off. As soon as you restart the water flow the water heater must recognize the flow, pre-purge the combustion chamber, spark, fire (that takes about 2 seconds on a Rinnai) and then heat that water up to desired temp. It can take several seconds.

I've done this at home where the wife got out of the shower. I got right in, ( we don't shower together much any more ) as she had turned off the water I had to start the water flow again. I had hot water immediately, but as the water ran through the pipes there was that slug of cooler water coming my way. When it arrived I stepped aside and waited about 5 seconds and I had hot water again for as long as I needed it.

This is why, when you make a move to a tankless water heater you look at your floor plan and figure the best location to, number one, minimize the delay in hot water delivery and optimize system efficiency. The mechanical room may not be the correct location for your water heater. The farther away you put the water heater the more pissed off you will be at it. You then have to begin "working around" the problem you just created. So, you go with a recirc system, the best of which is the Metlund Design system.

Many will simply install a pump on the unit. The Navien has a pump built in. Just be aware that when you install a recirc system you may very well find, and likely will find, that you will spend more to fund the heat loss of the recirc system than you actually pay for your delivered hot water.

I was the Rinnai rep in the New England territory for 22 years and now consult for them. I like to include that disclaimer fyi

 

[Jackfre]

It occasionally happens. Also you need to clean the flow sensor screen ever so often. Don't ask me how I know about that. Hot shower this AM turned into a very cold one

The necessity to clean the inlet filter is not the water heaters fault. You have dirty water. That inlet filters sits where the cold water ENTERS the unit. Your unit has a turbine on the cold water inlet valve that #1 reads the flow and the inlet temp. #2 it lets the unit know how much gas it needs to fire to satisfy the temp rise at that particular flow. It will alter the input depending upon changes to that flow. It is an essential and excellent technology in tankless water heaters. Some are better than others.

Keep in mind that the dirty filter is the "symptom" of your problem. Your problem is you have dirty water. You are sending that to your dishwasher, washing machine, brushing your teeth with it and cooking with it. Your solution is to put a cartridge filter on your cold water supply.

Your plumber should know enough to tell you about this as well as explain the CWS issue previously discussed on this thread. This is also why the tankless unit should always be installed with the isolation service valves.

Just an FYI, did you get a water quality test? I'm assuming you have a well. If you did not get a water quality test you may be crapping up your water heater.

 

[Chevy72pu]

I installed this one for the sink only when I built this shop in 2005. I ordered it from the Home Depot website. I think it was $189.00. It is a 220v unit and heats very well.

 

[James E]

Many will simply install a pump on the unit. The Navien has a pump built in. Just be aware that when you install a recirc system you may very well find, and likely will find, that you will spend more to fund the heat loss of the recirc system than you actually pay for your delivered hot water.

I was the Rinnai rep in the New England territory for 22 years and now consult for them. I like to include that disclaimer fyi

I have had Rinnai and Navien and have a Navien now. One way to get around the efficiency loss of having a recirculating system is to put a timer on it--which some Naviens have (mine does). I set the timer to start recirc just before we wake up and stop after we've gone to work/school. Then it starts back up at about 5 and runs for a couple hours. The rest of the day it works just like any other tankless unit.

It's a compromise, but a recirc is great when it's running because it gives us almost instant hot water at every faucet on the loop. To me, that's worth a few bucks a year in lost efficiency. I'm saving so much over the old, double 50-gallon-in-series system that came with the house that it really doesn't matter.

 

[CamarosRus]

I restarted this thread at post #25.

I failed to mention that I have nat gas available at my detached shop.....so may I assume that a NG tankless set up is less expensive to operate/own than 220V.

I'm reaching out for help here if you could please come down to my inexpereinced level.

Need occassional hot water to wash car, wash hands, wash parts, clean a paint brush etc etc AND planning on shower and sink in shop "bathroom"

FYI, I'm shopping for used restaurant style stainless sink/drainboard to use in shop area
plus above mentioned "bathroom" needs

Looking for best value brand and model ???

Thanks