water heater failed .. need a new one ... tankless?

[Music Lover]

I used to have a gas HW tank but changed to electric about 15 years ago, mostly so the tank could be moved from the middle to an outside wall and because I'd be able to change the tank myself in the future.

At the time my average summer monthly gas bills averaged $12 - $14 plus fixed charges (the HW tank was the only appliance using gas). So my basic run of the mill gas HW tank cost $13 a month to run. That included both the cost to heat the water and the losses.

Our cabin electrical bill for March to October last year was $220, that included electric HW, a wall AC unit, a fridge, a freezer, a stove plus the fixed charges. We were only there 40% of the time but the fridge, freezer, and HW tank were never turned off.

Based on the real world examples, I can't envision there ever being enough savings to justify switching to tankless.

 

[ERD50]

We have used a tankless hot water heater for 16 years. As soon as we got it our electric bill dropped $50 a month.

We can use the dishwasher, washer and take a shower without running out of hot water.

I'm also very skeptical. That kind of savings makes no sense, or maybe it wasn't from the tank-to-tankless switch? I'm assuming you went from electric tank heaters to electric tankless?

-ERD50

 

[bigadventure]

Hello, Pipefitter here,
If your buying a tankless to save money, you won’t be saving money. They cost more to operate in water usage and fuel.
Tankless tanks only heat water so hot. They rate them in “rate of rise”. So you have to know the ground water temperature to calculate how much hot water you get out.
I am on my 4th tankless unit. I replaced my 40 gallon tank 35 years ago. I have had Thermar, Bosch, and Rinnai tanks. There was nothing wrong with the old units. I actually sold them. There was no reason to replace them except the technology changed and i wanted to update them.
My latest tank is a Rinnai RUR199in. This unit has a circulation pump on it. I do not have a return line, but this unit comes with a Gundflow thermo bypass that’s piped into the farthest fixture. It is also a condescending tank. That means the exhaust is cold and the condensate is acidic. So it has to be treated before discharge. It also will turn the outside of the pipes black or green if not treated.
The biggest complaint my wife had was having to wait for the water to get there. Well the pump solved that. It works well. It came with a WiFi unit and you can download an App. These are terrible and Rinnai should be ashamed to offer them. I replaced these with a timer unit Rinnai offers. It works as intended.
Having endless hot water is nice. Dishwasher and wash machines these days have water heaters built in them. They are also pushing cold water washing. Have you seen the “cold call commercial”. Now there is only two of us and i think it is a bit over kill.
You can adjust the output temperature on a tankless unit. I found 120 to not be hot enough. I run my tankless at 125.

The new hot water tanks are not that good though. The Honeywell control sucks. You can not access the burner, for safety reasons. You need an expansion tank.

 

[aja8888]

Living in Texas. Two 2,000 sq ft single level homes (daughter's and ours).

Both houses 20 years old and so were the HW tanks (checked date codes).

Both had 40 gallon Bradford & White tank HW tanks installed in the attic (yeah, that is crazy, but it's Texas). Mine started to leak last summer and we had it replaced with same B & W American Made unit, gas fired. We had my daughter's changed out too and it was not leaking.

Cost was $1,375 for each unit, installed.

Hopefully good for another 20 years!

 

[Music Lover]

We have used a tankless hot water heater for 16 years. As soon as we got it our electric bill dropped $50 a month.

When I had a regular gas HW tank my summer gas bill used to be between $12 and $14 (excluding fixed charges). That not only heated all the water I used, it also paid for all the supposed standby losses.

 

[JoeWras]

The more I read about this here, and on bogleheads and reddit, I'm convinced this is a personal choice. Each solution has positives and negatives, and a lot has to do with the specific use case, installation location, and so on.

There is no simple one size fits all answer.

 

[WestUniversity]

Our house had two conventional tank water heaters that needed to be replaced. For about the same dollar amount we replaced them with one tankless heater. The brand is Navien. So far we are incredibly pleased. We’ve had it for about 18 months and it’s great…

 

[finnski1]

OP here ..
Getting a few quotes on the job. Will decide soon

Forgot to mention. I got a quote a few months ago from my oil heat company.
$2176 to remove and dispose old 40 gallon tank and replace and commission new one. It was going to be a SuperStore brand 40 gallon and required fittings etc.

Mine is an indirect installation where the tank is basically a second zone off of the main system.

I am also in NH (Southwestern area) and this quote was from November.
I was able to do a simple fix to mine and it is fine now. Didn't need the replacement.

 

[albireo13]

I have decided to go with a tankless heater, Rinnai RU199i. I emailed out to our neighborhood and got lots of feedback from other folks in the area. Most had switched to tankless and were very happy. It seems that the lifetime on tank heaters in our area was running 8-10yrs. That's about how old mine was. The tankless should last significantly longer, as long as I do yearly maintenance.

The common issue with the tankless was the lag for the hot water when you first turn on the faucet/shower. I get that now in the kitchen anyway since it's the other end of the house from the heater. I may install a small heater under the kitchen sink. I had been considering one, even before the heater failed. TBD. I will wait until we have the new system running before deciding on that.

 

[albireo13]

hmm ... Did some estimates and calcs and coming up with we are paying ~$3/month in water/sewer charges just in running the kitchen sink to get hot water started!

 

[bigadventure]

I have decided to go with a tankless heater, Rinnai RU199i. I emailed out to our neighborhood and got lots of feedback from other folks in the area. Most had switched to tankless and were very happy. It seems that the lifetime on tank heaters in our area was running 8-10yrs. That's about how old mine was. The tankless should last significantly longer, as long as I do yearly maintenance.

The common issue with the tankless was the lag for the hot water when you first turn on the faucet/shower. I get that now in the kitchen anyway since it's the other end of the house from the heater. I may install a small heater under the kitchen sink. I had been considering one, even before the heater failed. TBD. I will wait until we have the new system running before deciding on that.

I like this unit because it vents via regular PVC. B-vent is very expensive. Like $50 for 3 foot.
I recommend the timer control MC-195T-US. As I said before the included WiFi unit is terrible and so is the app.
Look up RinnaiGuy on utube. Lots of good information from him.
Realize that running a circulation pump and the tank cycling is not very efficient. But, i just hit the override button on the timer to turn it off when we are done.

 

[tb001]

We have the exact setup bigadventure has. Right down to the app replaced with the timer and the 125 degree setting. We have a recirculation pump on our house, like we had with our old tank heater. I see zero difference in lag time for hot water.

We’re in the process of setting up automation that will allow us to trigger the recirculation pump when we’re in the kitchen/bath so it’s not running all day. The energy use is pretty minimal, but I don’t like waste. I had wanted to use the app to do that, but it’s clunky enough we’re going to use a SwitchBot and just press the button.

Bigadventure, do you have a ups on the system? If so, what are you using. That’s my biggest (only) gripe with our tankless. If the power goes out it stops heating water, which I expected. But more annoying, if the power flickers, it resets the system to 108 degrees and you have to reprogram the recirc pump keypad. Whoever designed that functionality was clearly not an end user. It’s very non intuitive and a pita. I literally have to search for the one specific YouTube video that shows how to do it every time.

 

[bigadventure]

I do not have a UPS on the power supply. I have not experienced a power outage yet.
There is a button available, that you can use to activate the tank. I think it is hard wired and you have to activate it ahead of time.
My tank is in the basement on the south wall. The master bath is on the north end 2nd floor. I had extra wires at my thermostat so I wired the controller there on the first floor.

 

[tb001]

I do not have a UPS on the power supply. I have not experienced a power outage yet.
There is a button available, that you can use to activate the tank. I think it is hard wired and you have to activate it ahead of time.
My tank is in the basement on the south wall. The master bath is on the north end 2nd floor. I had extra wires at my thermostat so I wired the controller there on the first floor.

Aye, that would have been a great idea re the controller. Just to have it inside would be nice! There’s a spot on the wall inside right behind where it sits. I think I see a project in our future!

 

[ERD50]

The more I read about this here, and on bogleheads and reddit, I'm convinced this is a personal choice. Each solution has positives and negatives, and a lot has to do with the specific use case, installation location, and so on.

There is no simple one size fits all answer.

Absolutely.

On the con-tankless side (some are situation dependent):

A) Initial cost is higher.
B) If present electrical or gas feed isn't sufficient (tankless require a much higher supply to feed that "burst", vs low-and-slow for a tank), it might be very expensive to upgrade.
C) Same as B for venting a gas unit.
D) Higher maintenance? I read about pumping cleaner through them once or twice a year? Some have mentioned that the tank mfg recc draining/cleaning once a year as well, but I don't think that is anywhere near as important as with a tankless, because that heat transfer with tankless has to occur instantaneously.
E) More complicated? Possibly more repairs needed on average?
F) (edit/add from a recent post) May not work, or may get reset after a power outage?

On the pro-tankless side (some are situation dependent):

A) Smaller size, might free up space or allow it to be installed closer to faucet where a tank might not fit?
B) Endless hot water (but many never have a problem with the tank supply, making this a moot point for many).
C) Longer life on average? Maybe cost effective in the long run, but I really don't know. I've had tanks last 30+ years.

Neutral: I don't buy the big money savings for tankless. These things just don't save much, keeping water hot takes little energy, it is the heating it from ground temperatures in the first place that matters.

So it all depends which of those are important to your own situation.

-ERD50

 

[tb001]

I would add noisy and requires electricity to the cons. If your power goes out, not hot water.

Our gas bill decreased enough to notice after we had ours installed. Maybe $10-15/mo. But again, we were replacing two large daisy chained hot water heaters.

I think longer life is real would add and potentially less catastrophic failure if they go as a pro.

 

[Music Lover]

Neutral: I don't buy the big money savings for tankless. These things just don't save much, keeping water hot takes little energy, it is the heating it from ground temperatures in the first place that matters.

-ERD50

I agree that the savings are overstated. My summer gas bill when just a regular gas HW tank was using gas averaged $12 - $14 outside of fixed costs. They don't lose as much heat as claimed.

 

[Deuce]

Oh and for those that suggest turning down the temperature so you are not mixing cold in, please remember that the dishwasher or washer was designed for at least 120 degree hot water

Dishwashers will heat the water to the required temperature.

 

[Out-to-Lunch]

The more I read about this here, and on bogleheads and reddit, I'm convinced this is a personal choice. Each solution has positives and negatives, and a lot has to do with the specific use case, installation location, and so on.

There is no simple one size fits all answer.

+1. True dat.

 

[Aerides]

I have decided to go with a tankless heater, Rinnai RU199i.

So I have to ask, given my low patience for inconveniences IRL, but have you not had hot water for a week now while deciding?

 

[tb001]

So I have to ask, given my low patience for inconveniences IRL, but have you not had hot water for a week now while deciding?

This is the worst part of decisions re major appliances. That and the current shortages. We really need to figure out what model will replace our current 20+ year old integrated fridge and freezer now so we’re not stuck figuring it out while we have a freezer full of stuff making a mess.

We were lucky with the water heater. We had a two tank system so we were able to bypass the leaking tank while we decided. A good thing because it took some time to get the room dried out.

 

[albireo13]

So I have to ask, given my low patience for inconveniences IRL, but have you not had hot water for a week now while deciding?

Water is tepid. Have been going to the Y!

 

[Aerides]

Water is tepid. Have been going to the Y!

Yeah but what is your wife doing? I'd be in a hotel or...a lawyer's office lol...

 

[albireo13]

Yeah but what is your wife doing? I'd be in a hotel or...a lawyer's office lol...

She is a real jock and uses the Y too!

 

[JoeWras]

Good point about showering at the Y. Public showers are a good back up plan during times of hot water crisis, whether it be equipment failure or something else such as loss of power. Don't panic, just use the back up plan! Kudos for OP for taking time and not making a knee jerk decision.

I also noticed during Covid our water use went up slightly. This was because I was not taking my normal 5x per week shower at the public pool.

My dad grew up in a house without a tub or shower. It was one reason he became a plumber. To him, a public shower house was normal. This was in Chicago. Turns out that these buildings are now historic structures! Seriously, if you ever visit Chicago for architecture, do the normal stuff like the river boat tour, or Frank Lloyd Wright tour. But don't forget some of the other gems like the Chicago fieldhouses.

Here's the only shower my Dad knew until he went off to WWII.