New house build: tank water heater vs. tankless water heater

NorthCyd

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Kind of an off shoot of this thread. Run hot and cold water to your garage. Might cost a couple hundred bucks but its awesome to have a spigot in the garage.
I didn't do that, but I did put a sink in the basement in the utility room. Great to have a sink to do the gross stuff in.
 
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NebrClone

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Tank.

1. Tankless need a minimum flow to turn on, so they generally don’t work well for things like washing your hands, where you just want a little warm water.

2. Maintenance: descale descale descale. If you have a water softener not as big of a deal, but tankless require much more maintenance than a traditional tank type.

3. Cost. The energy payback is so long, you’ll need to replace it before it achieves it.


Maybe this has changed in the last 4-5 years when I did my research on a replacement. After talking with experienced folk and some actual plumbers (not the sales department…) I went with a traditional (high efficiency) tank style.
My tankless has a 3 gallon tank for hot water right away.
 

JP4CY

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I didn't do that, but I did put a sink in the basement in the utility room. Great to have a sink to do the gross stuff in.
I only had spigots on the sides of my house and now having one in the garage is awesome for washing cars, shoes, grill, etc.
 

CarolinaCy

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100% go tankless! BUT... I have one cautionary tale. Be sure that it's rated for your climate. I've had tankless on my last two homes (both new construction). The amazing thing w/ tankless is the gas bill is so low by comparison to traditional water heaters. And the constant hot water is awesome.

A couple years back Texas had the deep freeze and subsequent mass power outage. Being from the Midwest I knew to drip the water to keep the pipes from bursting. The mistake I made was I dripped the water only on the cold side. Because my tankless heater was mounted to an exterior wall the internal components were exposed to the freezing temps w/ no backup heating source. One of the control valves froze and cracked and leaked INTO the house. I walked into a dark bedroom and... squish... it had dripped dripped dripped through the wall and soaked the carpet adjacent to that exterior wall.

Both of my last homes had two tankless heaters - one for each half of the house.

I recently moved into Dallas and into a home built in the 60s. The house has a brand new traditional gas water heater with recirculating pump. I miss my tankless desperately. And because of the recirculating pump the water heater basically runs all the time (until the timer shuts it off), so my gas bill is ridiculous again. I'm getting ready to do some remodeling so plan to change to tankless during the construction.

The owner mentioned that he has a recirculation line/pump in his own house and his utility bills are high because of it, but he also said he'd never live without that in any future house.

The house will be a 1.5 story, with only 1 bathroom on the 2nd story (3 kids to share). Primary bath, laundry, kitchen, 1/2 bath all on main floor, finished basement will have full bath and wet bar. So most faucets are not that far from the water heater (which will end up almost directly below the kitchen), and I'm not sure I can justify the higher gas bill to get hot water a few seconds faster to my shower or the kitchen sink.

I had actually proposed using a hot water manifold, as I lived in a house in Johnston back in 2006 or so that was built with that. He said he'd get his plumber to quote that, but that seems like a better option as there is no increase in utility cost, and only slightly more install cost (separate supply lines to each faucet).
 

NebrClone

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One thing to maybe consider is that fact that with tankless, when the power goes out you have no hot water (i think this is the case?). That's not the case with a tank. It might not happen often so it might be worth the risk, but I think it's something to keep in mind.

I had someone try to sell me on powered venting of my tank so we didn't have to run the exhaust pipe all the way up to the roof, but I didn't go with it for that reason.

Edit: probably should specify I'm referring to tank powered by gas.
I have side exhaust on the furnace and tankless water heater. Love not having any pipes through the roof.
 

CarolinaCy

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Gas tankless - OK
Electric tankless - Nope

I saw a Tik Tok on this exact thing. It was many-year veteran plumber that was asked. I don't recall the exact answer but his answer was dependent on your energy source. If you have gas energy go one way and if you have electric energy go the other.

Kind of got lost in the original post, but it would be gas supply for whatever option we choose.
 

TXCyclones

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Tank.

1. Tankless need a minimum flow to turn on, so they generally don’t work well for things like washing your hands, where you just want a little warm water.

2. Maintenance: descale descale descale. If you have a water softener not as big of a deal, but tankless require much more maintenance than a traditional tank type.

3. Cost. The energy payback is so long, you’ll need to replace it before it achieves it.


Maybe this has changed in the last 4-5 years when I did my research on a replacement. After talking with experienced folk and some actual plumbers (not the sales department…) I went with a traditional (high efficiency) tank style.

As far as your "minimum flow" comment, the very first thing I did in both of my last two homes was remove the water restrictor washers from my shower heads so I would get a full pressure shower (I hate weakass showers). Even doing this I NEVER had a problem with low-flow conditions with a tankless heater.

Also, the water here is heavily calcified and I have never descaled a tankless.
 
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herbicide

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As far as your "minimum flow" comment, the very first thing I did in both of my last two homes was remove the water restrictor washers from my shower heads so I would get a full pressure shower (I hate weakass showers). Even doing this I NEVER had a problem with low-flow conditions with a tankless heater.

Also, the water here is heavily calcified and I have never descaled a tankless.

The feedback I got from friends and others on “minimum flow” was more to do with washing hands and things of that nature.

Regarding the descaling…. I can assure you your heater is subject to the same chemistry that applies to all other tankless heaters….
 
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NebrClone

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As far as your "minimum flow" comment, the very first thing I did in both of my last two homes was remove the water restrictor washers from my shower heads so I would get a full pressure shower (I hate weakass showers). Even doing this I NEVER had a problem with low-flow conditions with a tankless heater.

Also, the water here is heavily calcified and I have never descaled a tankless.
I remove all the restricters also. I want a lot of hot water.
 

Marcelason78

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Unless the 75 gal requires more btu’s and thus a larger gas line? Or the 50 gal doesn’t require the powered exhaust and the 75 does?
Even if both sizes were powered exhaust, the retail cost between the two is nowhere close to $2600. Not even half that amount.
 

CYdTracked

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Go with tankless. The savings you'll see in efficiency and lifespan alone are worth it along with constant hot water even if the initial install is more you'll probably go through at least 2 tank water heaters before you would have to replace it. The descaling is not a big deal, just buy a pump and a couple short hoses and a 5 gallon bucket, just hook up and flip the bypass valves and flush for an hour once a year. You still have to drain a tank water heater regularly to help with the lime build up inside that so I don't see how descaling a tankless one is any more of a pain, takes me a minute or 2 to switch all the valves and hook up the pump and then let it flush for about an hour before turning everything back the way it normally is.

Like someone already mentioned installing a water softener will help too especially if you have hard water. Would also recommend looking at putting a whole house water filter in too. Between that and a water softener not only will your water taste and feel better but it will increase the lifespan of all your appliances and fixtures by reducing the sediment and hard water that would flow through and gradually build up. The whole house water filter system is pretty simple and inexpensive. We have the 10" Big Blue like this one Ten-Inch Big Blue Whole House Units – Pure Water Products, LLC and can find the filters on Amazon for like $60 a 4 pack. We change ours about every 4-6 months and its amazing to see how they go in white and come out rusty colored. Must of really had some bad water from the city 1 time as about a month or 2 after changing a filter our water pressure went way down all the sudden. Talked to my plumber and he said try changing your filter even if you just did it recently. As soon as I turned the water back on with a new filter the water pressure was back so the filter apparently was really plugged up with something that was going through at the time. Glad the filter caught it and it wasn't going through everything in the house!
 

MeanDean

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I didn’t even know electric tankless was an option. That seems crazy.
I have one in my condo here in FL. Because it's a multistory building there is always concern about tanks leaking and running down into lower floors and causing lots of damage. It is mandatory to change out tanked water heaters every 10 years minimum here for that reason. I'm on the top floor and went with the tankless. I think at the time it was only available as a German manufactured source. I don't remember it being THAT much more costly. Maybe 30% and some of that was for the electrical connections and fusing. Gas is not available here so was not an option.

As others said, another benefit is that it takes up way less space. So my utility closet went from a furnace and tanked water heater to a furnace and the tankless unit, which is about the size of two or three shoeboxes. Which opened up a bit of space where the tank had been for some storage - which is at a premium in most condo units.

I have never heard about descaling though. Maybe because the water here is from soft water surface source (Lake Okeechobee).
 

Mr.G.Spot

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Go thankless and gas if possible and absolutely on the circulation pump.

Look at the new Essency Water heaters. These are a new twist on the tankless. A little hard to describe, but they give a 20 year warranty on the system and 6 years on parts and labor. They are connected to wifi and app.works.

I put two in, and with the boost feature, can act like 80 gallon heaters.
 

ISU_Guy

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Yesterday, I just got $2800 quote for 50 gal water heater (mine is a power vent).
I feel like that is like $1000 more than 5 years ago, but I guess inflation may have played a role?
 

Mr.G.Spot

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Yesterday, I just got $2800 quote for 50 gal water heater (mine is a power vent).
I feel like that is like $1000 more than 5 years ago, but I guess inflation may have played a role?
A replacement for my 80 gallon heaters was going to be $5,500/each. Ouch. Spent a similar amount on the Essency product.
 
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Helser 83

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After reading through this thread, I get the impression that several people don't really understand the concept of a tankless heater and how they actually work.
 

JP4CY

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Yesterday, I just got $2800 quote for 50 gal water heater (mine is a power vent).
I feel like that is like $1000 more than 5 years ago, but I guess inflation may have played a role?
Bradford White 40 gal power vent was $1244 for me in 2020.
 
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clone52

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Hey fellow Fanatics, we just signed the paperwork to build a new house that will be ready sometime this coming summer, and one of the things that my wife and I have been wrestling with is: do we go with the 50gal gas-fired standard tank water heater that the builder will supply, should we upgrade to a larger 75gal (~ $2600 upcharge), or upgrade to tankless water heater (~ $3000 upcharge)? Another option we would have is to add a hot-water recirculation line throughout the house for something like $1500, so we'd have instant hot water at all taps.

We have a family of 6, and the 4 kids are all teen/pre-teen girls, so showers take like 7 hours.... only a slight exaggeration there. What is everyone's experience with tank vs. tankless, and also a recirc line? My concern is that the tankless can't keep up with that kind of hot water demand, but the upcharge on the 75gal tank seems pretty high.

Would love to hear thoughts and feedback. Thanks!
If you go the tank route, I would highly recommend a heat pump one. Ours is electric, efficient and keeps the basement dry.
 

Cloneon

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Hey fellow Fanatics, we just signed the paperwork to build a new house that will be ready sometime this coming summer, and one of the things that my wife and I have been wrestling with is: do we go with the 50gal gas-fired standard tank water heater that the builder will supply, should we upgrade to a larger 75gal (~ $2600 upcharge), or upgrade to tankless water heater (~ $3000 upcharge)? Another option we would have is to add a hot-water recirculation line throughout the house for something like $1500, so we'd have instant hot water at all taps.

We have a family of 6, and the 4 kids are all teen/pre-teen girls, so showers take like 7 hours.... only a slight exaggeration there. What is everyone's experience with tank vs. tankless, and also a recirc line? My concern is that the tankless can't keep up with that kind of hot water demand, but the upcharge on the 75gal tank seems pretty high.

Would love to hear thoughts and feedback. Thanks!
I designed for both: standard tank in utility room and on-demand closer to the supply. Having designed it that way and plumbing it that way allowed me to start with the standard and 'add' the on-demand inline at each of the sources. What can I say, I hate waiting for the hot water.
 
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