Another question about tankless water heater. I have searched and read

[rnln]

Hi guys,
It's time for me to replace my water heater. I have searched and read for hours, but still can not make a definite decision. If any of you made your decision and are happy with the tankless, please give me some knowledge. I know the first advantage on tankless is saving space. On saving energy, most people talked about saving gas, what about electric bill and convenience/maintenance? To those who passed on the tankless, can you tell me the reason?

Also, I have confusion between tankless electric and tankless gas. Most people just said tankless, I assume it's electric, but when I went to homedepot website, I see there is also tankless gas. What is the advantages and disadvantges?

If I gettankless, elecrtic or gas, is it just simply swap it in place of the old water gas tank, soldering the input and output copper pipes? I am asking this question because I see many thread people are talking about the cost of repiping, scaling, filtering, regulating, etc ... Also, I've seen some pictures of it after installed. Why $2k installation (someone told me)?

Your experience is with 110v or 240v unit?

If it matters, the existing gas burn tank I have now is A.O.Smith 74 gallons. I see wet water underneath it. Distant between the tank to bathrooms are between 30' to 40'. We currently have no problem waiting for hot water and no problem running out of it, even though my kids love to dance in the shower.
Thanks.

[Bill Douglas]

Around here most people are moving to tankless gas and we almost always use Rinnai #1 Tankless Water Heater Buyer's Guide | Rinnai

[rwest]

Hello,

I installed a tankless a few years ago, it was gas and it cut my gas use in half- from two therms to one- a therm costs a couple bucks! You will not save enough to re-coop your costs. The other drawback is the cold water lag, you have ten seconds or so of cold before hot gets to you and if you turn water on and off for shaving, you'll have a blast of cold every time you turn it back on. Mine froze up on me one winter when -17F air back drafted down the stack, several months later it burst. So now I'm back with a tank. The only real benefit I saw was being able to take as long of a hot shower as you want. Because of my experience, I've curiously read a lot of articles on them and I think that a common thread is that a tank is cheaper when everything is taken into consideration.

For installation, you will most likely need to increase the size of your gas piping to account for the massive amount needed to heat all that water. Instantaneous electric water heaters probably wouldn't be able to supply enough heat to warm up water for showers, just hand washing.

Good luck,
Rutager

[JJ 911SC]

Originally Posted by rwest

... Because of my experience, I've curiously read a lot of articles on them and I think that a common thread is that a tank is cheaper when everything is taken into consideration...

Agree, rather expensive with only 1 year warranty.

They are very popular in Europe where space is at a premium. In a 2500 sq/f bungalow for 2 of us, don't care about wasting a bit of space.

[rnln]

I see why the prof need to redo some pipes. Thanks.

[Jim Richards]

Hi rnln, I have a gas tankless water heater in my SoCal house. I have mixed feelings about it after a couple of years of ownership.

You'll probably want to get a gas unit instead of electric for more cost effective heating. The gas units need to be vented to the outside, and they need a very special flue. The flue on your current hot water tank is not sufficient. Their gas requirements may require your gas supply piping to your tankless heater to be increased in size from what you currently have. Speaking of size, make sure you have a unit that can more than meet all household needs at the same time (personal opinion).

The tankless water heaters bring the water temperature up fairly quickly; however, the water in the pipes between your tankless heater and where you're using the water are initially full of cold water. That creates a time lag to get hot water. It's nicer to have the tankless heater located closer to where you're using hot water. Showers and running the clothes washing machine are no problem after the initial lag. Where it's more of an issue is the sinks. On/Off and low demand may not keep the water flow through the tankless heater at a high enough level to stay on and heat the water coming to the sink. Apparently, there's a possibility to make this less problematic by implementing a recirculating system with the tankless heater. I don't know enough of the details to explain it here, but some of the other guys like look 171 should be able to fill you in. My plumbing system has some lines stubbed in to add a recirculating system one of these days.

We are currently only at our SoCal house a week or two at a time, a few times/year until we retire. So, our use for hot water is only limited to those times. It saves us a noticeable amount of money on our gas bill, as compared to the old conventional hot water heater we had. Even after we retire, we should still see savings over the old system. And, when we travel, our gas consumption will drop back to practically nothing during those times.

I hope this helps you in your research on this, rnln.

[Chocaholic]

Same consideration here. Original AO Smith tank is 20 years old and still working fine. Have decided to stay with tank for many of the reasons above. Our dilemma is between electric and propane.

[Rot 911]

Never had a tankless. Nice thing about a regular water tank is that I can install it myself. The newer tanks are really well insulated, which cuts down on heating costs.

[vash]

Mine is kicking butt. Went tankless with gas. Going on ten years with no issues. Only downside is a power outage will make me suffer cold showers. Next time, I'll have the electrician give me a plug and switch to hook up a tiny generator.


Sent via Jedi mind trick.

[IROC]

Originally Posted by Rot 911

The newer tanks are really well insulated, which cuts down on heating costs.

Yeah, the wife and I were talking about this the other day. We have gas water heater/oven/stove. Water heater is a tank unit. Our gas bills during the summer (not using the heat) average about $9/month. That's for a family of four/stay at home mom/cooking each day, etc. Hard to beat the cost.

[JJ 911SC]

Originally Posted by IROC

... Our gas bills during the summer (not using the heat) average about $9/month. That's for a family of four/stay at home mom/cooking each day, etc. Hard to beat the cost.

That is cheap.

Our gas bill is also cheap but more than double by the time they add all other fees

[Rusty914s]

I use tankless for projects but for my own house, I installed a side arm. Whatever you do don't buy your stuff at a big box store.

[aschen]

we have a gas tankless, I like it just fine. You can take a 3hr shower if you like.

Our house and unit is small though, it willnot run two showers simultaneously.

In the end I dont think it matters too much. Gas is cheaper than electric either way. The biggest advantage is it really cleaned up our utility closet IMHO

[creaturecat]

the heat exchanger expired on our Rinnai, 3 years into ownership.
they covered the exchanger, however it was 600 dollars in labour, to install.

[pitargue]

We have an outdoor gas tankless heater. (Silicon Valley) Just the peace of mind of having an old rusty tank leaking in the basement (which the last one did) is worth it to me. The tankless works well, w/ about 1/2 a gallon of water before it gets hot on the 2nd floor shower. (Save this 1/2 gallon for the garden since we are currently in a water crunch.) In our case the gas lines from the main feed to the tankless is extremely short, which in earthquake country is a good think I reckon.

If your demand for hot water is minimal, it's an energy savings from not having to heat up a tank of water constantly. This is true one travels a lot.

I don't think I'd go back to a tank as I like the perceived convenience of a tankless water heater.

With that said, will someone like Nest create a "smart" water heater w/ an app for further energy savings?

[NY65912]

I switched to a gas tankless from a 50 gal HWH. I like it, endless showers and a really hot whirlpool. I am a plumber so doing the install was not too bad. The hardest part was running the intake/exhaust out from the mechanical area which is not on an outside wall. Do not buy the Navien brand. Tagaki was bought by AO Smith, I'd go with that or a Rinnai. The other benefit is there is a lot more space for other junk in the mech area.

[Icemaster]

Bosch tankless, gas. 12 years ago, wouldn't think twice about doing it again. Installed myself, sized the pipe and compensated for the combustion air with an additional external intake. Total out of pocket was around $900 and half a Saturday.

Don't let it get overly complicated.

[UncleRay]

Thanks for the replies to the OP's issue and wishing you good luck with the project. Here is what I'm looking at doing and maybe some of this can apply to yours. Likewise I have problem with old tank style at the cabin. Based on the helpful info I'll probably install outdoor propane tankless. Removal of old tank frees up valuable space in the bathroom. I can convert the existing exhaust roof vent into a ceiling mounted bathroom fan. Longest run from outside location to kitchen sink, shower and bath sink would be about 15 feet as the kitchen shares the same wall. Unit would go on outside wall next to the water heater. This gives a very short fuel supply line. Winterizing would be a must each fall. Thanks again, Ray

[JJ 911SC]

Originally Posted by creaturecat

the heat exchanger expired on our Rinnai, 3 years into ownership.
they covered the exchanger, however it was 600 dollars in labour, to install.

Typical scam... Cover the $25 part but your are stuck with an exorbitant labour cost which is almost the cost of a large tank.

Was the plumber driving a Cayenne Turbo by any chance?

[dad911]

Have tankless in a vacation home, great for that application, can run 2 showers non-stop.