DIY Home Improvement Forum banner

Tankless water heater - NEED HELP!

9K views 39 replies 12 participants last post by  tompehonda 
#1 ·
Hello everyone. I am in the process of buying my first home which has a water heater tank in the kitchen!!!! (takes too much space). I would like to buy a tankless water heater and convert the area into a pantry. Can I put the tankless water heater in the pantry since they are small??? Do they generate heat, niose???? Also, I have 2 bathrooms, with one bathroom having 2 sinks, a kitchen sink, washer and dryer, and dishwasher. Will the tankless be able to keep hot water say if 3 things are running?????? One more question; are they easy to install or do I have to have it professionally installed???
THANKS
 
#2 ·
You can put them in a small room, provided that the manufacturer-required working clearances are met and provided you have an exterior wall for the vent/intake to penetrate.

They'll typically require a larger gas line than a conventional tank.

For household use, a tankless should have no problem keeping up.

They aren't silent by any means. Probably somewhere between a furnace and a conventional gas-burning tank.

They aren't a DIY job. You really need to hire a pro to do it. They're rather complex compared to a conventional water heater.
 
#3 ·
the person living in there has a gas burning tank in the kitchen in what it seems to be a pantry. if noise was not a problem for them and you're saying its quieter than a gas burning tank, then I think it should be ok. Are the air intake requirements the same as conventional??? Can I put the tankless in the interior wall of the pantry?
 
#4 ·
if your not opposed to it you could go to a tank less electric heater they are very quiet and can be put almost anywhere.If you concerned about them heating additional outlets it not much to modify the plumbing thats pretty much DIY stuff.I would advise going with a pro for the electrical part though.I ran two smaller ones together for now and they produce extremely hot water to one full bath the laundry room and the kitchen with DW and thats two adult and three kids
 
#6 ·
Tankless electric will probably require a huge electrical service upgrade to the house. :no:

Most tankless will get you about 5gpm of water at full pressure. Shower is 2.2 GPM and a sink is 2.2 GPM...... do the math. People in Europe have been using them for YEARS, so obviously they work out fine. People have a hard time adjusting to the idea of reduced flow from their hot water system.

What happens when you have more than a 5gpm demand on the hot side? You'll just have reduced pressure. The water will still be hot, however.
 
#5 ·
depends

If your water heater is already electric, I would go ahead andinstall an electric tankless by yourself.

Gas tankless heaters are far superior in the amount of hot water they produce for multiple uses. If you don't have gas avaiable I would recommend a pro install it. If there is already gas and a reasonable place to vent it, go for it yourself.

P.S. Tankless will save you quite a bit of money. Too bad you didn't put it in last year. Uncle Sam would give you $300 back on your taxes !!!
 
#7 ·
to be honest once I got rid of the old water heater and put the tankless in I got better water presure.Maybe the old one was just pluged up I dont know and also I am running smaller units to each part of the house that will need it.I put the main feed on a water manifold so as to feed each part and ran 3/4 pex to each then conected it to the required 1/2 in copper for connection to the inlet and outlet sides of the tank.As for the power supply all it took was some 220 wire ans a new breaker so far all is great with dont know why everyone is not useing them.It also droped my gas bill about 60 bucks a month electric only went up about 3 dollars
 
#8 ·
I had a gas tank, put in an electric tankless and love it; I too did it primarily for space savings. Size stems from what you use, not what you have. So you have 2 showers, 4 sinks, dishwasher, and a washing machine. What are the odds 2 people are showering while someone has clothes in the laundry and the dishwasher is running? That's for you to think about, not for us to tell you. I personally have 2 showers but no kids in the house, so there are never 2 showers running at the same time. The only issue we've encountered so far is in the dead of winter when the incoming water temp is icy.... yay for Michigan winters :no: I bought a Delta high pressure - low flow shower head (about $30) and the problem is fixed; never can tell the difference. Note I didn't say low pressure, they're completely different. Good luck!
 
#13 · (Edited)
Please read the link posted in Alan's post above--it is a true story posted by me. Just b/c you had adequate service to support one HWOD unit doesn't mean you can add a second--after you have read my story that Alan posted, you'll realize what an incredibly difficult issue this can be.

Alan, if you're watching this thread, I'd like to thank you for posting that link. I tried to PM you to say thanks, but I'm a forum noob and don't have enough posts to be able to use the PM function.

There's an old saying, "No man is totally worthless, they can always serve as a bad example". Sadly, I find myself in that situation now--hopefully someone else can avoid the cost, delays and aggravation that I have endured, all b/c I just jumped right in and bought before I investigated adequately. I don't mind being the bad example if it saves someone else all I have had (and have yet) to go through :blush: !!!!

One very frustrated Dugly :cool2:
 
#14 ·
Yerug,please don't get me wrong here I am not saying a home owner dose not have to check things out before he or she jumps into this.All I meant was if the had the power supply which I assumed he did it is not hard to hook one or even several up.The cost for buying tank less I found to be minimal and the installation as not expensive but I knew I had the power supply and was already re plumbing the house.Many HO cant simply pop one in as I did and have had bad experiences with it but I was only trying to show him how inexpensive it would be both on start up and in the long run.Any HO who didn't do their homework before a change like this would be sort of asking for trouble,but I guess thats one reason he is on here is to get the good and bad sides of a subject like this then he could check it out and make up his own mind
 
#18 ·
SSSHHHHH--We don't want people to know about our pheasants!!!!

Not to take this off topic, but YerDugliness, who in their right mind goes on a vacation to soutwest Kansas? :wink:
I grew up there, I guess it's true when they say "you can take the boy out of the country, but you can't take the country out of the boy". I've lived in this urban insanity that is Houston for 25 years, what with their daily homicide counts and all, and I guess as I age I long for the simplicity and tranquility of a home where the county just had it's first homicide in 20 years last summer. It was just a vacation home while I was working, but being retired now I have more time to devote to the upgrades--it will be a retirement home soon :yes: .

Pheasant (and other wildlife) are one of the main reasons I go there to vacation and plan on retiring there. The home in which I'm installing this HWOD might be used as a B&B someday, particularly during hunting season. My mom ran the local rural mail delivery route, 94 miles per day. Every year she had to complete a "wildlife survey" as part of her job. She intentionally under-reported the pheasant population so as to reduce the hunting pressure on the area, and it STILL earned the top spot in the state for pheasant population density.....I guess it's true what they say about the best laid plans of mice and men.....

The deer are returning, too--there were NONE when I was growing up there in the laate 1960's, but last Thanksgiving my SO and I were driving a dirt road that is the CO/KS state line and ran across a herd of about 20 or so. We made nightly trips out there to watch the herd and take photos. 20 miles west in Walsh, CO, they had to shoot a brown bear down off a telephone pole out in the country--how weird is that????? Walsh is probably 200 miles from Durango, the only mountainous terrain in that area...

Like the title says, we don't really like for people to know about our well kept secret......:eek:

The home ought to be in good condition by pheasant season, if you'll PM me I'll hook you up with free lodging as my way of saying thanks for all the help! By then I might even have made some connections with local farmers who would open their land for hunting, we'll see how that goes.....

Dugly :cool2:
 
#19 ·
I get requests for "green" technology almost daily.
Gas tankless's are worthwhile, they save roughly about 30& off the hot water bill, but the installation costs can be inhibiting where gas & venting has to be run as opposed to a simple tank type replacement.
The major savings on gas tankless is the fact that they heat at about 85% efficient as opposed to tank types that heat at 60%.

I have done the math on electric tankless's and in all honesty I feel like a crook if I don't inform customers that they save almost nothing.

The standard for heater tanks standby heat loss efficiency is generally no less than 15 btu per sq ft of surface area for the tank.

(1 therm is about 29.3 KW)

Lets say a standard 40 gal heater is about 2 ft diameter by 4 ft tall...thats about 29 sq ft of surface area.

That means 435 btu/hour, 3.132 therms per month or 7.2036 KW per month.

I'll overestimate the cost of eletricity and call it $0.20 /KW.

My math isn't perfect, but you save $1.50 a month there for an electric tankless.

The average homes service panel for electric is 150 amp, impossible to service a 120 amp appliance along with a full homes demamd for electricity, so this requires a sertvice upgrade on top of the initial installation.

I saw a guestimate at $1500, not likely...trenching runs around $50+ /lineal foot for an excavator alone.

I'm sure my math is fuzzy, buit even if I'm ten percent off, I just don't see how these electric tankless's are even in business.

Gas tanless, on the other hand have proven to save, atop the convenience of not having to wait a half hour because your 16 yr old took her nightly half hour shower.:mad:
 
#20 ·
ahhhhhhhhhhhh but you fail to mention if you didnt have to do an up grade on your electrical and you did the replumbing yourself and got a good deal on the electric tank less how much would you save ( just kidding) but I did see my gas bill go down about 60 a month and electric only up about 3 dollars but I didnt have to up grade or do much replumbing so maybe I got off lucky I dont know but I do know I checked it out throughly before I bought it so I wouldnt be sitting here with a huge instulation bill or no hot water
 
#23 ·
Don't forget, part of the homework in these units is output to obtain a certain temperature rise. 8.2gpm might be true at a 50 degree incoming water temp for unit A, but at 70 degree temp for unit B.... 70 degrees incoming is not even possible in my area. I mention this because this is the only time we had an issue with ours; the water temp in the winter here in Michigan is much colder than the water dept. had told us to expect. the output sounds great, but make sure you know what your incoming temp is.
 
#39 · (Edited)
Don't forget, part of the homework in these units is output to obtain a certain temperature rise. 8.2gpm might be true at a 50 degree incoming water temp for unit A, but at 70 degree temp for unit B.... 70 degrees incoming is not even possible in my area. I mention this because this is the only time we had an issue with ours; the water temp in the winter here in Michigan is much colder than the water dept. had told us to expect. the output sounds great, but make sure you know what your incoming temp is.
This is an important point, as the temperatures achieved by HWOD units are limited by the temperature of the inlet water and the flow rate. My Stiebel Eltron electric HWOD unit requires 0.5 gallons/minute flow before it will even fire up. I dealt with this by buying a special shower head that maintains the water flow through the shower at a steady 1.5 gallons/minute. The water heater so far has not failed me, although I must admit I do not think the heater is functioning as specified. I'll measure inlet and outlet temperature next time I'm in KS and get the differential, if it's not as specified I'll call the source, they have a technical service line.

I plan on making a batch-type solar water heater this summer to preheat the water to the WHOD unit. My only concern right now is whether or not I can avoid scalding temperatures, as there will be times in the summer when the solar heater will elevate the inlet temperature for the HWOD to the point that it will not need to fire up; in fact, the solar heater will heat water to a higher temperature than I can achieve with the WHOD unit alone.

This solar water pre-heater will be made with the water tank from the gas-fired tanked heater my HWOD replaced. Now, how's that for irony :thumbup: ???

Dugly :cool:
 
#25 · (Edited)
Out here some people are using solar preheat with storage to feed the tankless and depending on the day the tankless is just part of the loop no need to fire up.
The monthly newsletter published by the electrical cooperative that provides our power in Kansas included a feature on such a device. It used the tank of a regular hot water heater in what looked like an insulated plywood box with a salvaged storm window on it. The top was angled to catch the suns rays best at an angle determined by the location's lattitude.

It looked like a simple and effective project.......interesting.....

Just wondering, Bob10, if there is a day in which the solar rise is adequate and the HWOD unit doesn't need to "fire up"/activate, will the unit still pass water? I'm not an engineer so I don't know if there are solenoids in there to open gates or if it's strictly open to heat-and-pass.


Dugly :cool2:
 
#27 ·
Yerdug no it wont work tank less are pressure activated or hot water on demand you have to turn the water on so you open the pressure which activates the heater but i guess it could be turned way down.Even on hot summer days my incoming water is not something I would want to jump into unless I was recouping from a hangover
 
#28 · (Edited)
Rinnai rep told me the unit only kicks on when the water pressure drops and it senses a lower temp. The temp of water is set by the consumer the tankless unit isn't going to overheat the water and create a scald hazard. More info is available at their website. Dept of Energy research for solar is in Colorado because it has the most clear days.
 
#31 ·
plumbermark I am not going to argue with you on here that is not what this forum is about.I gave the man my honest estimate of what my electric went up.and after seeing what the gas was costing me and getting a letter from my gas company stating rates were going up and my avg bill would go to near 500 a month I shut all my gas off and went all electric it still cheaper.I will be hooking up propane for cooking though.As for the cost two Titan n-120 units hooked together cost me 145.00 each a certified electrician friend hooked up the electrical but only had to take the wire to a box I would say 8 ft away no charge .I just had an insurance inspection two months ago from Allstate when I changed policy to a replacement policy they asked about it when they saw it but didn't have any problem with it and yes it is marked in the policy that I have them I was not being a jerk when I answer what you had wrote and you can do you math all day if you want I know how much my bill went up and how many people live here and shower each day we are not dirty people.My clothes are clean and yes we even eat off of real plates and wash them every day.The good thing about a forum like this is everyone can give an opinion I tend to not give out answers unless I have something worth a darn to add if I don't I just read and learn.I had what I thought was a valid point to make to the mans question, I did I really like my electric tank less heaters if you don't OK we are all entitled to are opinions Thank You
 
#32 ·
I think a large part of the problem people have here is locations are not listed. Betweeen gas and electric where I am gas is always cheaper for now. Having said that other parts of the country have different access to power and costs. Electric heat for water or space would at least double if not triple my monthly costs.
 
#33 ·
Bob10 I agree I lived in Memphis for many years and all the utilities are one their MLGW Memphis light gas and water.They have some of the best rates in the country and my bills were always low in the summer maybe 35 dollars winter about 100-125.Now in NW Pa. and just one of my separate bills here is more then all 3 here
 
#34 ·
Clasact, no argument intended..I tossed in a few humorous comments to break the monotony of the math, it IS pretty boring.
keep in mind -

At the heart of learning, there will always be disagreement.

Bottom line, I have never met anyone who claims electric is less cost than natural gas to heat.. it isn't possible with current market energy prices.
LP or oil is are different story as they're petrolium based, perhaps you were using LP and I missed that detail.

Someone looking to swap a tank type electric to a tankless electric would be in store for major disappointment.

We can basically say that all electric water heating devices are almost 100% efficient, whats lost in translation is the actual cost of electricity vs NG, electricity prices reflect transmission loss to get it to your home.

I'm saying that there are no situations that an electric tankless would benefit someone who has a tank type NG or electric heater. period.

On electric heaters, nearly all the input energy is absorbed through the elements, tank type or not...the only difference is standby heat loss.
I posted an estimated $1.50/month above, for the sake of argument lets double that to $3.

If you look at your electric bill you will probably find you cut down on other appliance use, maybe at that same time you stopped using your A/C, but it's almost impossible to have a $3 water heating bill on electric.

I can definitely see the $60 drop on your gas, but somethings wrong with that $3 estimated increase on your electric...you can't physically take a daily shower for $3 a month unless you have friends in high places at the light co.

I will also tell you I have lost several potential customers in the last year alone by being honest about switching from tank type electrics to tankless electric...I have absolutely nothing to gain in the honesty.

I get constant calls for green technology, much of it is hogwash, much of it is truly legite. Trouble is that so many plumbers willingly cater to customers delusions without being responsible and doing their homework.

To further illustrate my point, I called Seibel Eltron once to ask for efficiency ratings...
He kept reiterating how much money a tankless saves over a tank type...I asked him about how an electric tankless would save over an electric tank type ~NOT tankless in general~...he pummeled me with the incredible savings on standby heat loss.
I then asked him for some figures, he had none, no estimate on how much energy a tank type loses, just phrases like "one hundred percent of all heat loss is eliminated", "amazing" and "incredible"...no figures.
I then gave him some figures, he wouldn't disagree.

There are applications where an electric tankless might benefit a homeowner, but they're comparitively rare in cases where you have an oil, or propane heater and just so happen to have a 200+ amp service that has enough left to accomodate 120 amps.

I'm a plumber, I stand to gain by NOT bringing these points to light with first time customers...but the green craze has aroused alot of snake oil salesmen...I just can't hop that train, not my cup o' tea.
 
#36 ·
I'm just going to hijack this thread and not start another, since my problem is very identical to the original poster's.
Same deal - older house, water heater in the kitchen taking up valuable space that I would love to use as storage/more cabinet space, etc. Current tank wh, gas, is from 1990 I think, so must be well overdue for replacement, I am in the middle of total renovation (to a point where I'm replacing a lot of drywall and electrical and all plumbing). I am the only one living in the house with 2 baths and a kitchen.
Now I was thinking of going with a tankless - save room in kitchen, possibly save a few bucks, and the unit is not very expensive (found a few for around $1200 on the net). Now I already have a gas line running to the install location (used for old WH). From what I understand I will need a bigger line?
Question 2: Can I confine a tankless WH in a space the size of a large kitchen cabinet? I saw clearance req's - 12" top and bottom and 1" sides, 0" back. Said nothing about front. I will have one vent pipe going to the roof and can cut another through the wall. Otherwise I have to install it outside. I am kinda paranoid about gas heater inside the house, in the kitchen, about 3 feet from my stove... Maybe outside is a better option?
And for those of you who do installs for living - how much, on average to come hook it up? Considering I will already have plumbing ran to it, it will only need gas hook ups?
Thanks,
Tim.

edit: electric is not an option. I am on 100 Amp service for the whole house as is, seems that's the requirement just for the water heater. Although install seems easy for an electric unit, and they are cheaper... I was quoted $1500 to run a 200amp service... I dunno about that.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top