Your thoughts on tankless water heaters

scramble

Premium Member
Joined
Jan 15, 2010
Messages
13
Location
Mary Esther FL
I wanted to get your thoughts on tankless water heaters. Our current hot water is very old and very small. My husband wants to replace it with a large standard tank unit. I read an article in Consumer Reports that left me with the feeling that the tankless models don't have the muscle to deliver really hot water for an entire house. Any thought from your experts would be greatly appreciated.
 

Jake

Appliance Tech - Admin
Staff member
Joined
Aug 24, 2004
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100,764
Location
McMullen Valley, Arizona
I don't know anything about them, but other techs. or members can reply to your thread here and give you some input.:)

Jake
 

service

Premium Member
Joined
Jun 18, 2010
Messages
6
Location
tx
I've been fortunate to see tankless heaters in action in a few countries. Granted these were older tech models, but they are always installed in the bathroom/kitchen. Single tank setup is a newer setup - I would trust CR on it, but if there's a specific model you have in mind post it?
 

ShanonT

Premium Member
Joined
Sep 1, 2011
Messages
5
Location
Liberty, SC
When we lost our water heater in 2008, my husband, who is a mechanical engineer, did a cost benefit analysis of tankless vs. electric.

We have a 500 gallon underground propane tank and I wanted the former. He also included the handsome rebate given from Uncle Sam. After checking the specs on heat transfer efficiency (which he specializes in) for each type of unit and the cost off propane vs. electricity....the numbers showed that at that time (and still today in 2011)the electric water heater is not only more efficient, but more cost effective over an 8-10 year time period.

The tankless did have a payback period, but it was 8-10 years out. His determination also assumed that the unit never breaks during that time or needs servicing. My husband also looked at the robustness (is that a word?) of the design and decided he didn't trust the tankless unit would last.

The electric unit has it's element in direct contact with the water which is 98.9% efficient (heat transfer). A flame under a pipe is much less efficient (I forget the exact number) so you need more propane to heat the same quantity of water. I would have wanted a unit large enough to heat enough water to run the dishwasher and take a shower. We found if I also wanted to run a load of whites in the washer, I would need an even larger unit which gets much more expensive. So I would have less options for when I could do chores. I would have to be more conscious of what I was running and when. Plus, we knew we would probably move in 10 years and never realize any payback.

If you also need to install a propane tank and lines...well....we didn't do that calculation (as we already had the tank), but you can see that now your pay-back time is much much much further out.

I like the concept of the tankless and think it would work well in a cabin, barn or summer home, but for now, the power plants (which are only like 60% effiencient) can make and send electricity to your water cheaper than a flame in the shorter term. The well meaning folks selling tankless units were astounded when my husband showed his excel charts to them. If you trust the design and plan to have your property for many years (over 10), and already have access to gas, then you may want to try tankless. Be sure you get the right size for your needs.

I hope my two cents helped some folks. I would ask that you use your local electric and propane or natural gas rates and do your own checking to see how the two stack up.
We didn't look at the environmental impact. Some might counter that propane burns much cleaner than a power plant and that this is more important than the money spent. Can't argue that one.

Cheers,
Shanon
 

ShanonT

Premium Member
Joined
Sep 1, 2011
Messages
5
Location
Liberty, SC
Excellent Consumer Report article on tankless heaters!

That was well worth the read.
We bought a $200 electric tank and never even considered a propane fired water tank due to the extra LP piping needed.
Fabulous :) article link. Lots of great facts and considerations mentioned.
-Shanon
 

phoenix8

Premium Member
Joined
Jun 11, 2010
Messages
2
Location
Kansas
I realize this thread is old but I thought someone might be interested in some additional information.
I have a small, full-service salon behind my house- two chairs, one shampoo bowl. Because of limited space, I went with an Eemax electric tankless water heater. It supplies the shampoo bowl, the sink in the color bar and the bathroom sink. I have been running it for seven and a half years with only one major problem; the water company shut of the water for repairs without notification and running the unit with no water burned out an element. Eemax sent me two new elements, plus a spare set, just in case. They had improved the elements since I purchased the unit and they are considerably more durable. Because I live in an area where tankless is not as popular because of hot summers and cold winters (people believe they don't work well with cold ground water), I have not been able to find an experienced technician. So, I really had to learn the ins and outs on my own. Here are the pros and cons I've experienced.
Pros:
The unit is tiny- approx. 11" x 9" x 4" and the space I have is at a premium.
It provides as much hot water as I have needed (I would have to have at least an 85 gal. tank because of recovery time).
It is incredibly energy efficient- it only runs when you need it.
The cost of the unit was $700, less than an 85 gal tank.
Cons:
It requires two dedicated 220's and uses 80 amps. Fortunately, I had my service upgraded to 200 when I renovated the building.
Temperature is affected by water pressure- when I am shampooing a client's hair, it is not a good thing to have someone flush the toilet!
Minor Annoyance:
Temperature is affected by ground water temp.- In the summer, it is perfect- in the winter, I have to adjust the water temperature quite often.
Overall opinion; though it gave me fits while I was learning how to use it, it works for me!
 

dta721

Premium Member
Joined
Oct 30, 2012
Messages
3
Location
Ottawa ON
I still have a 13 years old RHEEM gas-fired rental HWT, will replace when broken with another gas-fired HWT.
Unless you have not sufficient space in the basement that drives you to have a tankless unit, I don't want to change for a couple good reasons:

1. No apparent savings, return on investment when you have to pay for more up front, for rental it is about $45 monthly vs $25 for conventional HWT, times 15 years it is a lot of dough :(.
2. The so-called unlimited hot water has a flaw: cold shower sandwich, Google this key words to find out more.

If it ain't broke (with regular HWT), why fix /change it, at extra cost?

In fact, my colleague nexty cubicle got the hype, changed to tankless, only to get back to his normal HWT right after. Of course it is his opinion, mine too :)!

IMO
 

devildog

Premium Member
Joined
Feb 17, 2013
Messages
2
Location
midwest
i dont have a tankless water heater..but 2 of my neighbors now have converted to them in the last 8 years and they just love em. endless hot water. just important to get the right size unit for your needs.
 

Koinz

Premium Member
Joined
Jan 2, 2009
Messages
16
Location
PA
I had a 2 takagi tankless heaters TK3 (larger units for whole house). The first one started to leak after 7 years, I was never impressed by it's performance though. It was natural gas fired and because it has to heat the water as it's passing through the unit, it seemed like the pressure was always lower. Takagi would not warranty the unit and instead gave me a reduced price on their newer equivalent model. I didn't want to have to re-plum everything so i went for a second unit. That one lasted 5 years before it started leaking and again they would not warranty the core. I was done with them after that. Crappy units and they don't stand behind theyre warrantly. No savings whatsover over the years of using them.
I now have a bradford white gas fired tank type water heater. Water pressure is back and I never run out of water - There are five people over the age of 18 living in the house.
If someone were to ask me about a tankless, I would definitely recommend against them. Of course, your scenario may require one, but I have not been happy, so that's my story and I'm sticken to it., :3:
 

arstb

Member
Joined
Apr 5, 2014
Messages
1
Location
los angeles, ca
I must agree with you Devlidog!

I purchased a tank-less water heater and since i have a lot of tenants and whatnot it tends to keep the water hot every time someone takes a shower or a bath and the unit saves me on electricity costs and its not in use when know one is using it, so it works great and it takes up a less than a third of the space as my old HWT.

the best tank-less appliance repair in los angeles btw :)
 
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