I'm considering a tankless water heater.

[PlaytheAces]

I put a tankless in a few years ago. Here are some random observations.

First, I had it installed primarily because the water here in Vegas is extremely rough on water heaters (not to mention fittings, but that's a whole 'nuther story). I figure the tankless unit should outlast 3 to 4 tanks given our water.

Second, you pretty much need a 3/4" line if you go natural gas. I had the larger line installed with the unit.

Third, when I had it installed the Feds were offering a hefty tax rebate. That, along with the rebate from the gas company cut a third of cost off it. My total out of pocket after the rebates was around $2k. Considering I've had neighbors pay close to $1k just to have a new water heater tank installed, I figure I did okay.

I was quite surprised at the gas savings. Running a tank was costing me about $30 a month. The tankless unit cut the cost in half.

Lastly is the performance end of it. Remember I live in Vegas where summers are hot. Hot as in over 100 degrees 3-4 months of the year. During the summer, taking a shower now means barely adjusting the water to the warm setting. The water is already so warm, the tankless unit doesn't have much work to do. The water is hotter than it was with the old tank, which acted as a buffer. In the winter, there's a noticeable difference as well. It takes longer for the hot water to hit (I adjust the unit to circulate hot water when the wife is getting ready for work so she doesn't have to wait too long). And you have to adjust the water well into the hot zone, unlike summer. I notice the seasonal differences much more than I did with a tank. Not necessarily a good or bad thing - just different.

So am I happy? Yup.

I hope I never have to deal with a hot water tank again.

 

[sipowicz]

It's a tankless job.

 

[scooter123]

Consumer reports says they aren't a good choice. The problem is that none of them feature an all Stainless Steel heat exchanger due to Stainless Steel not being as efficient at heat transfer as mild steel. BTW, a heat exchanger 15% larger would provide a solution to that issue but a water heater with a 50-100 year lifespan isn't exactly appealing to the manufacturers. The end result is that in an average of 10 years they will need to be replaced and the payback period for the cost difference is between 15 and 20 years. This means that a tanked water heater will cost less over a 10 year lifespan than a tankless even if the tankless is more efficient. BTW, if the heat exchanger on a tankless splits it will put out as much water into the home as a tank water heater unless there is a leak sensor and water shutoff valve installed.

 

[smokindog]

I'm not trying to sway anyone's opinion, much like discussions on which press to buy (SS v P, Red V Blue V Green V ...) Tankless heaters make sense in many applications and don't in others, YMMV.

I installed a Rinnai (top end 9.8 GPM gas) that has the sensors/cutoffs for water built in and automatic. It also has a moisture sensor that can be tied into your alarm system for leaks. These are pretty sophisticated units and the newer ones are showing up with dual heat exchanges. All brands that I looked at have similar cutoffs/features built in. Someone else mentioned above, buy what you can get serviced and what the supply stores sell.

I replaced two 50 gallon water bombs in the attic of a two story home with one tankless. Pay back is a very specific calculation against use and many other factors can influence a decision. To me, the OP's situation screams for a tankless. I've got a detached garage/workshop with only cold water in the bathroom and will probably install a small one out there rather than take up the spaced to keep a bucket of hot water on a stove!

A "proper" install will include a filter at the inlet which needs to be checked and changed as required. Also, descaling is an easy and periodic maintenance activity that will extend the unit life. The warranties are also much better for the tankless. I got lifetime parts at the time of my install, YMMV.

As to Consumer Reports, ... It's not your Father's magazine anymore

Consumer reports says they aren't a good choice. The problem is that none of them feature an all Stainless Steel heat exchanger due to Stainless Steel not being as efficient at heat transfer as mild steel. BTW, a heat exchanger 15% larger would provide a solution to that issue but a water heater with a 50-100 year lifespan isn't exactly appealing to the manufacturers. The end result is that in an average of 10 years they will need to be replaced and the payback period for the cost difference is between 15 and 20 years. This means that a tanked water heater will cost less over a 10 year lifespan than a tankless even if the tankless is more efficient. BTW, if the heat exchanger on a tankless splits it will put out as much water into the home as a tank water heater unless there is a leak sensor and water shutoff valve installed.

 

[cobra44]

I was also considering a tank less unit, and I still am.
Several friends purchased them. The big problem is they must be cleaned (the ones I know of) once or twice a year. Any minerals pretty much destroys them. It takes a little time to do this.
They do save gas as compared to a tank model.

 

[mtgianni]

Get a 40 gallon tank heater. Put a good drain system in your cabin and turn the pilot off and drain the system in winter when you are not there. You should fill in 5 minutes or less and if it is a cabin you should be on a pump, well or spring. IMO, you will never reap the cost until you get up to a family of 6, used every day.

 

[labworm]

It's a tankless job.

Tanks Sip, your post brought a smile to this MA mug.

 

[Buttercup]

My parents installed one at their house. I do not like it. It is very difficult to regulate the hot water level with theirs. It seams like it is always to hot or not hot enough. Waste more water trying to find the compromise. They said they wouldn't do it again because the cost of the u it and proper installation is hard to recoup for very little benefit.

 

[35Rem]

Small cabin? One or two occupants? Why would you need even a 40 gallon tank?

The cost for occasional use can't make sense to me. Get an inexpensive smaller tank and winterize it when you leave.
It's only going to run when you turn it on, just like the tankless.

 

[carpriver]

We have a rehiem tankless heater for our house. we found our natural gas bill dropped in the warm months and we were not heating water in the heater. Yes the cost is higher to install. When our teenage grand daughters visit there is always enough hot water. We can run the dishwasher, the washing machine, take shower and have no drop in water temp. We have had no problem with the heater. you must drain and flush with white vinegar once a year to prevent mineral build up on the heat exchanger. the flush takes a couple hours, but that is quicker then flushing my tank heater to get the minerals out of the bottom of the tank. That is what kills a tank heater.

It's a choice like everything else.

For a cabin that isn't used often it maybe the thing, as they can be drained easy, no gas or electric used to heat water when you not there.

 

[cmore]

thank you all for your input.
This is the unit I am considering:Takagi T-KJr2-IN-LP Indoor Tankless Water Heater, Propane - Takagi Hot Water Tankless - Amazon.com@@AMEPARAM@@http://ecx.images-amazon.com/images/I/31TJLqEvuuL.@@AMEPARAM@@31TJLqEvuuL

It is only about $100 dollars more than a 40 gal unit.
and has very good reviews on Amazon.
I also plan on a gas shutoff valve.

 

[Krell1]

When I had a walk-in tub put in for my disabled wife the 40 gal HWH,
Didn't even make it....
Installed a 75 gal. NG HWH that the plummer said would take about one hour or more to come to temp.
How about :35 min?
Can use the dish washer, cloths washer and take a shower and all hot water....
Comes on once or twice a day....
And about $2000 less what I was told for the Rinnai system I was looking at.
I would have to live to 95+ to break even.......

When I looked into it the cost was a bit higher. Just the cost of the exhaust pipe through the roof was expensive enough. If I subtract the gas I use to heat the house, the remainder is the cost for hot water. My standard 50 gal water heater works just fine for me and it would take 20 to 25 years of gas savings to justify the cost. I'll be long gone by then.

 

[crsides]

I went tankless a couple yrs ago and will never go back.


Charlie