tankless water heater

[Sonders]

this isn't for garage, rather the whole house. Thinking of ditching our old 40 gallon electric water heater and going with a tank less unit. Are the electric tank less units any good? Looking for pro's and con's of going this route. Thanks in advance for any replies.

 

[Randy in Maine]

I did that only mine was a Rinnai propane unit. Worked flawlessly for 5 years and is still working flawlessly for the guy I sold it to. The one I bought was not set up to do my radiant heat (I did not have radiant heat when I bought the on demand water heater).

Cut my electric bill by about $40 a month.

 

[HoosierBuddy]

https://www.amazon.com/gp/product/B002635ODW/?tag=atomicindus08-20

Looks like people are pretty positive on that one anyway.

Cost for installation might be really high based on the electrical requirements. It isn't just going to be able to be hooked up to the circuit your tank is currently hooked to.

Phil

 

[Stuart in MN]

A whole house electric tankless heater is going to require well over 100 amps to operate.

 

[ddawg16]

I did a lot of research into tankless when doing my 2-story addition....I stuck with a gas tank heater.

You have to look at your usage and location.

Be aware, an electric tankless needs a LOT of power.

Tankless makes sense IF...
1. Your usage is in the morning and a short time at night.
2. If the tank is a long distance from the POU (point of use) and you can get the tankeless closer.
3. You don't have gas.

But......
If you use hot water all day long....you might be better off with a tank heater. My gas unit had a 12 year warranty....chances are it will last 20 years. I can replace my heater 2-3x for the cost of a tankless.

Do you have gas? If so, it's by far the best bet.

If not....you might want to look into the hybrid units. It's basically a heat pump. Uses between 1/2 to 1/4 compared to a tankless. If you are in a mild climate, better efficiencies. Real cold....it might have to resort to backup heating elements time to time.

 

[Northislander]

My gas unit had a 12 year warranty....chances are it will last 20 years. I can replace my heater 2-3x for the cost of a tankless.

That's what the sales people want you to think but trust me they are engineered to fail soon after warranty. And those engineers are getting good seldom do a warranty replacement anymore. But then again that is with British Columbia water maybe others have experienced different with better or worse water.

As for electric on demands lots of power needed most panels don't usually have the room to add one unless they were oversized in the beginning.
Our local plumbing wholesaler was carrying one brand for a while they had so many issues with them they quit carrying them.
If you don't have natural gas you could always look at a propane unit we have installed lots of Rinnai propane units no problems.

 

[tomroblee]

Hard water is a problem with tankless water heaters----especially electric ones

 

[ddawg16]

That's what the sales people want you to think but trust me they are engineered to fail soon after warranty. And those engineers are getting good seldom do a warranty replacement anymore. But then again that is with British Columbia water maybe others have experienced different with better or worse water.

As for electric on demands lots of power needed most panels don't usually have the room to add one unless they were oversized in the beginning.
Our local plumbing wholesaler was carrying one brand for a while they had so many issues with them they quit carrying them.
If you don't have natural gas you could always look at a propane unit we have installed lots of Rinnai propane units no problems.

OMG.....I better replace my water heater....it's about 15 years old.......

the sky is falling....the sky is falling.............

Northislander.....

I think California is going to be pretty easy on it.

 

[Northislander]

OMG.....I better replace my water heater....it's about 15 years old.......

the sky is falling....the sky is falling.............

Northislander.....

I think California is going to be pretty easy on it.

HaHa you laugh now but try to get 15 years out of a new one. I replace tanks that are 25 years old but the one i replace it with i'm back in six or seven years and they all run off the same city water.

 

[Adk Mike]

Tankless water heaters are best in places where you don't have the room for a tank unit.
condos or house build on slabs.
Where you have a basement and room I prefer the tank models. In New York State where I live the regulations require high quality insulation in the units. They don't fire very much unless your using them taking a shower etc. just my thoughts. I sold both. I have a tank unit at my home and I prefer Bradford White. The brand the plumbing trade uses.

 

[Showkey]

High initial cost.........

High maintenance, especially with some water types.......

Often no saving on operating costs..........
Often no saving on water or sewer costs........
0ften there is no return on the investment on tankless.

Wait a long time to get hot water to distant faucets.........as long as several minutes to 5 minutes. We have an electric tankless in a condo in Florida..........it heats water but everything else about it *****. We are happy it's a casual use vacation ion home.

My Nat gas tank unit with a gravity supply loop for instant hot water at any faucet at any time costs $10 per month to operate, last one lasted 20 years with no service. Do your home work on tankless.........

 

[dragonballz]

Why would a tankless take longer to get water to the point-of-use than my tank? They would be located in the same spot.

 

[driftpin]

We remodeled our 3,000 sq. ft. 3 b.r./4 bath CBS construction single-story home and installed a Rinnai RU98 natural gas tankless water heater. The cost to operate is much less than the 40 gal. electric 220V water heater preceding the Rinnai. We have an endless supply of hot water. It needs a flush once a year to remove scale at the heating element, easily done by the homeowner.The architect and the contractor both recommended the Rinnai, and we followed their advice. It uses 20 amp 220 V electric in the branch circuit panel.

The original house had copper lines, and we spec'ed copper for all new work for potable water delivery. Gas delivery is below-grade cast iron, which was the most-expensive part of the installation. The natural gas line was at the end of the block, a neighbor who was doing a substantial remodel and we divided the cost of the gas line to our homes. We're in the middle of the block. If anyone else wants to connect, we get some $ back.

Here are a couple of pics of the install, and the manifold.

 

[BearsFan315]

6 years ago we did an addition and put in a gas tankless to replace the gas 30 gal we had.

would NOT do an electric tankless unless a small POU a full size one requires 100-200A depending on flow rate. we did a gas rinnai and will never go back. 1.5 bath house with 3 kids, never run out of hot water and taking a shower you loose no hot water if someone is running wash machine or doing dishes. other that loosing a lil pressure.

Make sure you look at flow rate in gpm as well as what the cut on flow rate and cut off flow rate are . i sized mine for what we use, and works great, never an issue, and we can control the temp of the hot water via a panel in our hall way. usually leave it at 115 all year round. stock will go up to 120, flip switch in panel will go to 140.

 

[Radix2]

this isn't for garage, rather the whole house. Thinking of ditching our old 40 gallon electric water heater and going with a tank less unit. Are the electric tank less units any good? Looking for pro's and con's of going this route. Thanks in advance for any replies.

Where are you located? Ground water temperature is a big factor in on demand sizing. What flow do you require 1 shower or 2 or a combination of draws?
What size electrical service do you have ? are there at least 4 open slots for new breakers.. where is your panel vs the water heater...

Some questions to consider

 

[Showkey]

Why would a tankless take longer to get water to the point-of-use than my tank? They would be located in the same spot.

Because there is no hot water in the tankless. So the lines before and after the heater are cold. The heater body is cold. The minute you open the faucet the water moves and the burner or Element is slow to start. Then it has to warm the pipes then then the cold water and the water is starting at 45-60* and you want the shower to be 110*. You get cold then more cold then luke warm, them warm. It takes minutes even approach the warm comforts of the shower or what people might call a HOT shower. Especially with electric.

A recirc system defeats the whole theory and purpose of tankless. Plus you can not do a gravity recirc system with tankless.

The wait time also effects the dish washer and wash machine when you call for a hot wash cycle.....or the dish washer has to heat the water.

Someone asked the distance to the service entrance. Makes a huge difference on the install for both gas or electric heaters. Often gas line needs to upsized. In my condo the tankless heater is within 4 ft of the panel. For obvious reasons cost of the wiring. The closest bath is 20 ft of pipe that takes the 5 minutes. The distant bath is 40ft of pipe........

 

[59 wagon man]

to get this back on track for an electric heater you need to find out what the incoming water temp is ,then you can begin to size a heater to work for you. just a quick little point to ponder. you heat the water in that tank for almost 8,000 hrs per yr without using any hot water

 

[Showkey]

Agree back on track:

The 8000 hours is the sales guy talking.........
Current cost to heat water for 8000 hours could be between $96 and $480 or $8 to $40 per month.

 

[HoosierBuddy]

I'm on the fence about going tankless NG myself with my next unit...but the one thing that you guys haven't discussed that is a BIG advantage to old-school gas tank modeled water heater is they require zero power to operate so you can grab a hot shower or have hot water to wash dishes even if your power is off.

If you've ever been without power for days....that is a tremendous advantage.

Phil

 

[Voi]

this isn't for garage, rather the whole house. Thinking of ditching our old 40 gallon electric water heater and going with a tank less unit. Are the electric tank less units any good? Looking for pro's and con's of going this route. Thanks in advance for any replies.

I have a natural gas tank-less. Don't know much about electric. One disadvantage of tank-less is in homes with bathroom/laundry/kitchen etc. spread out. My house is about the ideal design with all of the bathrooms stacked on top of each other and with the kitchen sharing a wall with one of those bathrooms.

I'm on the fence about going tankless NG myself with my next unit...but the one thing that you guys haven't discussed that is a BIG advantage to old-school gas tank modeled water heater is they require zero power to operate so you can grab a hot shower or have hot water to wash dishes even if your power is off.

We had a three day power outage back in 2013 and ran our tankless water heater off of an inverter in our vehicle. Would charge cell phones while taking showers or washing dishes and has hot water for the price of idling our vehicle.

I've thought about going with Dewalt's cordless inverter to back up ours.

 

[tlmartin84]

My 2 cents:

I built my home in 2008 with a 50 gallon electric tank. Wanted to try a tankless but didn't, because they were fairly new and I had several plumbers and electricians tell me they had issues.

I just built my shop, and purchased a RHEEM RTE 13 open box through ebay for 100.00. It requires a 60 amp breaker. I was concerned this may be to small due to our ground water temps. HOWEVER it turned out to be PERFECT for the shop. https://www.amazon.com/dp/B003UHUSGQ/?tag=atomicindus08-20


Now the comparison.......

With the tank I have better water pressure, the tankless reduces it some. Water is hot much quicker at the tap with the tankless. It takes time to empty the lines out at the house. Other than that, no differences for me.

If I did it over, I would have placed one of these at each point of use at my house and offset the costs by not needing to run as much pex.

 

[Jackfre]

I am heavily biased here. I have worked with Rinnai for 25 yrs. Positioning a tankless is important. I always recommend that the job be priced in the current water heaters location. Once done, I ask that you take a walk around the house and see if there is a better spot for the unit. Closer to the point of use. Don't perpetuate the mistakes of the original low cost bidder. My 180000 btu tankless (RL75) will at a 70* rise produce 4.3 gpm. It will fire at .4gpm and hold operation down to .25gpm. The 75 is the .82EF model. The .95EF 199,000 units will make a bit over 5gpm at the 70* rise.
Recirc with tankless can be problematic. Why do I want recirc? Here in CA, while we are getting washed away this winter, the norm I think is for dry. A lot of people out here have lost their wells. While all my life we have gone energy energy energy, here in the west the mantra is water water water. I just added the new wifi module to my tankless. With that I have a wireless motion sensor in the M Bath and a wireless push button tucked up under the cabinet next to the kitchen sink. Essentially it is on-demand recirc. As well, if the unit is unhappy it will tell me on my phone. The wireless is backward compatible to all the Rinnai water heaters made since 2006. The RUR model from Rinnai has the circ pump built in.
The tankless I had in my MA home ran for 13 years. I never touched it. It was a pre-production Australian model. When we sold the house I had to put in a new American approved unit. I took my saws-all and cut the old one in half to see its condition and it was clean as a whistle. Water quality is a big deal. Know what you have. Water quality hammers tanks as well. Flushing with white vinegar may be necessary.
My gas consumption dropped by over 40% when I put mine in and we had two teenage girls at home then. Showers did not have to be scheduled.

 

[yeldogt]

Tankless work great when sized and positioned properly. We did a master bedroom w/bath addition and put an electric tankless in the closet -- it's basically in the bathroom and sized for a single outlet -- house is on a slab and running the hot line from the storage heater was too far and almost impossible. We did another for the shower at our shore house -- again dedicated unit just for the shower -- that one is NG. Both of these houses also have traditional tank units.

They need to be close to the use point or you are waiting for the hot water -- doing a recirculation loop defeats the reason for having it. Also -- be very careful if you are on a well ... they have a max delta .. if the incoming water is too cold in the winter it will not heat properly.

We bought a ski place with an electric unit for the whole house -- hated it. The lights dimmed every time the unit came on -- the house was too spread out. Also -- we had to get a dishwasher that heated the water as the water entering for the second cycle was always cold.

They keep getting better .... and if the house is properly designed for one they work better still. I'm not putting one in my new build and would never think of doing one if I had NG -- what's the potential savings?

 

[vettex2]

anyone try one of these for just a sink ?

http://www.ebay.com/itm/Mini-220V-I...hash=item43f3361906:m:maKn8OUx5XnNfMMK1p57hSw

 

[Sonders]

wow, lots of great info here. I noticed that the tank less units require a lot of power which was one of my main concerns. Our current electric 40 gal unit was centrally located for the existing house, but the addition is further away on one end of the house. Usage is mainly in morning, and at night as kids are in school and wife and I both work during the day. I am leaning towards just going with a hybrid unit then possibly a pou unit in our new master bath in addition. We do not have natural gas available at our house, but have LP tank for furnace and fireplace. Wouldn't really want to tie anything else into that as tank is only 250 gallon. That is why I was looking at Electric units.

 

[ddawg16]

A POU unit is a very viable option for a remote bathroom.....unless you also want it to supply the bath or shower.

You might want to look into recirculation units

Put it on a time so it only circulates the water prior to when you normally need it.

 

[ctgoodman]

wow, lots of great info here. I noticed that the tank less units require a lot of power which was one of my main concerns. Our current electric 40 gal unit was centrally located for the existing house, but the addition is further away on one end of the house. Usage is mainly in morning, and at night as kids are in school and wife and I both work during the day. I am leaning towards just going with a hybrid unit then possibly a pou unit in our new master bath in addition. We do not have natural gas available at our house, but have LP tank for furnace and fireplace. Wouldn't really want to tie anything else into that as tank is only 250 gallon. That is why I was looking at Electric units.

Electric units will not save you anything. It will cost a fortune to run for a whole house. We looked at this when we built and a tankless electric unit would have needed more than 100 AMPS. We then decided to put in the 250 gallon propane tank and go with a 199K BTU propane tankless. We have a fireplace and a cooktop on it too. We rarely use the fireplace. We might use about 60-75 gallons of propane a year for a family of 4.

 

[Retlaw 66]

I did lots of research a few months ago. John's post #5 sums it up very well.

I've had a 80 gallon electric tank that, so far, has lasted 28 years! Researched the tankless but decided on the conventional tank. Went with a basic 50 gallon unit. Natural gas is also not an option for me.

To reduce costs, I added a timer to control the power.... It's on for about 4 hours in the morning for my daily noon shower. Still provides warm water at midnight but haven't tried a hot shower at that time. Timer consists of a 2 pole contactor for the 240v with the coil activated by a simple timer at a nearby outlet. I plan on moving the basement timer to a more accessible location like the master bath.

In conjunction with the timer, a tempering valve was added to the outlet of the tank. I can turn up the tank temp to 150 degrees and the tempering valve will reduce the temp to house to 110* or so. This will reduce hot water use and keep the tank water hotter while it's powered off.

Another neat system is a add-on heat pump for a tank. Check out the Niles Geyser here:
http://water.nyle.com/r-series/
Check with your power company to see if it qualifies for a rebate. It wsn't quite efficient enough to qualify for my POCO's $500 rebate.

Another great link for LOTS of water heater tips:
http://waterheatertimer.org/

I agree a point-of-use tankless may be a good choice for your addition.

Been thinking of getting a tankless just to heat the water a bit for washing my cars!

 

[yeldogt]

Your location?? ..... If you live in a cold climate you should spend the money getting everything tied to the NG line. That's the best bang for the buck. Get a typical tank. We spend about $25 month heating our hot water ... there is no payback when you have NG. Even with a furnace -- moving from 85-95% is hard to justify.

 

[Showkey]

Been thinking of getting a tankless just to heat the water a bit for washing my cars!

Wouldn't $10 in PEX or $40 in copper get hot water from your water heater you already have ??? Think all in my hot water addition to the garage faucet was less $40.