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

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.

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

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

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.

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

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. SmileWavy

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.

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.

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.

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.

That is cheap.

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

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.

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

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

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?

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.

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.

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
http://forums.pelicanparts.com/uploa...1403660354.jpg

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?

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

We've had two tankless water heaters for five years now with no issues whatsoever. We went with propane over electric when I looked at the specs and saw the electric sucked a mind blowing 160 amps at full tilt. They are both 6.5 GPM Rinnai installed by the plumber at the time of construction. Since our house is a flat, single story with 70 ft. between the kitchen & main bath, I chose one at each end of the house instead of two tank heaters or one with a constant recirculating system. One is near the kitchen and laundry room, while the other is for the back bathrooms. For the one servicing the bathrooms, we have a circulating pump activated by a button that brings the hot water to a bath in about a minute and a half. It's true there is a wait for the hot water without the pump. Cost wise I think I figured out it cost 17 cents a day (the rest of the house is electric) but there are only the two of us. In the five years I've had the propane company refill the tank (250 gal. connected via one of those yellow, flexible lines) once after the initial installation & fill up. I still had a decent percentage left, but they called up with a special price of $1.99/gal. I would never buy any type from a big box store. I read they were supposed to be descaled periodically and did mine after about three years and found no scale at all, but your mileage might vary. It's true the new tank heaters are more efficient, but there are also reasons for choosing tankless.

Scale filter should be installed somewhere the water enters the heater. Tell you the truth, I have been messing with and talking to engineers and sales people about these units for over 15 years before they got popular. I was the sucker that tested them on my own house way back then. I like it, but it MUST be maintained. Descale is one of those chores. CLR is suggested, but vinegar will work but not as effective. As far as those big blue scale filters are concern, I have never seen one clogged or need replacement. I often wonder if they are doing its job (i am sure it is).

The one thing they usually don't tell you is that the igniter sometimes go bad or have carbon build up. That's part of the routine maintenance they almost do not ever tell you about.

We switched to Rinnai tankless gas a couple of years ago. The only downside is hot water lag. I am the cook of the house & I wash my hands frequently while doing it, of course. The two other family members have an extremely irritating habit of only getting a cold water drink from the kitchen sink. Despite my frequent rants, I spend a lot of time waiting for hot water.

Ian

Is that a DIY job?
The pilot keeps going out on my tank water heater... so I think "no problem I will just put a new thermocouple in there".
I pull the pilot assembly out and it has some weird thermistor thing that was broke.
Being a tech I was able to get out a soldering iron and do a work around... but the old tank water heaters are not as simple as they used to be (or long lived).

Not sure what all the complaining about "hot water lag" even with a tank WH I have to wait for the hot water to get to wherever I am using it.

I live in a small beach house and it just would be nice to save the space of a tank water heater, I presume you can't install them outside?

Everyone seems to be able to get GAS tankless but I'm not able to get gas (well my wife may disagree with that). What about ELECTRIC tankless? From what I read/hear electric tankless is not such big a cost saving over a new highly insulated tank type.

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

Mine is an outdoor unit. Huge cost advantage by not having to dick around with exhaust pipes. You have to buy an outdoor one. I cannot put exhaust piping on mine. I have a square exhaust vent that is fluted against rain in front of the unit.

Bonus. My bathroom is right near my gas main. So we put it very close to the shower. I get almost instantaneous hot water. I flip on the water and I have just enough time to ditch my panties. I jump right in.

Mine has a remote control I mounted inside my bathroom closet. It uses that lightweight wire, similar to doorbell or telephone cord. I can adjust water temp, shut it off, etc. it also gives me messages to unit health. For instance it flashes a "FL" when I need to flush the unit with vinegar to remove scale. My water is great. I haven't done it yet.

I went with a rinnai.



Sent via Jedi mind trick.

Ours is mounted outside, too. No exhaust piping required.

Did it upstairs, left the tank downstairs. Why ? Best of both worlds (keep a tank in case water is out, hurricane, quake, whatever)...

+ Tankless is great when there's a risk of water damage from a burst tank (upstairs).
+ It's great to give unlimited fresh warm water (i.e if you live with a woman and 3 teenage daughters).
+ takes little space, none inside (on an external gas one)
+ $50 electrical savings, $3 extra in gas ;-)

- Costs a lot more to buy and install & piggy back into your water supply.
- Another box on the side of your house, yeah (not)
- Takes longer than a tank to get in gear and provide warm water
- Did have some temperature control issues if you want lukewarm (summer), it cut out on me. Obviously it's more sensitive to water inlet temps, so takes longer in winter, and in summer it would give me water that was too hot and then cut out... we installed new faucet "mixers" and it helped but I'd say it sucks at lukewarm, admittedly not a huge deal.

All in all, given the price of a tank, maybe a new clean tank isn't that bad: kinda like buying a diesel or hybrid, good MPG but how long before you recoup your $ ?
If you got the cash and need infinite hot water, or like me had a tank upstairs that was taking closet space, why not. It's alright. But not a life changing thing... You can go either way and be fine !

So... if you buy an outdoor one you don't need to build a cabinet for it (Like you would for a tank water heater if placed outdoors).

I'm liking this more all the time!

No. It is sealed against weather.


Sent via Jedi mind trick.

I put in a Rheem tankless in my last house.The Cdn govt at the time was giving a $800 grant to encourage installing them. It required a larger gas line than the previous tank style heater. That,s part of the extra expense. It also requires a direct vent to be cut thru the wall instead of up the chimney with the furnace.
I was never able to see a significant saving on my gas bill.
My biggest complaint came after 10 months use.
I returned from a 2 month trip to Florida and it wouldn,t light. It has a 1 yr parts &labour warranty. The warranty requires you to deal with a call centre (in Georgia I think).
they sent a new ignition unit overnight which means 2 days to Canada ,that didn,t fix it.The factory authorized repairer then ordered a new board after more time on the phone. 2 days later that didn,t fix it either. They then authorized a new unit which was in stock at the local home depot. That did fix it BUT I was without hot water for 6 days. My wife was livid.
A standard gas water heater would have had parts available in town and would have been repaired on day one.
This was for a unit under full warranty. The parts only warranty covers year 2-5. Then I would have had to pay for the labour or do the diagnosis myself and work thru the 800 number.
We have since moved and now have installed a new direct vent gas tank with a standing pilot. (Which will probably last 20 yrs here).

I always push the owner so we can install it outside, unless its up in the attic. The vent pipes are big bucks. I like it outside for one major reason: Servicemen do not ever have to be inside the house. No dripping water when you descale, all the mess is outside. Yes, like Vash said, only a cap is needed and no SS vent pipes that cost an arm and a leg.

Yes, its a DIY deal, but it will take a bit of time. I still have not done it to my own yet, but I have change them out for clients a couple of times. They really last a long time if you have a water softener.

Now water heaters do not last 20 years. Those were the days when we were kids. Rheem make a great water heater, but not tankless. I wouldn't buy their tankless if you paid me.

No cabinet needed. They need to vent. I am working on a house right now where the owner (wife) really dislike the looks of having it outside (existing), so we are relocating it in the attic. Cutting roof, SS vent, gas, drain lines, recirc. pump and timer and electrical is going to be crazy money. But, she likes to not see it. :rolleyes: I say, good for her and she need to put her foot down goshdarnit. She's actually pretty damn nice to deal with.

like this scott.http://forums.pelicanparts.com/uploa...1403764896.jpg

A couple things I forgot....

- The consensus seems to be that GAS tankless provide great savings. Electric ones NOT.

- Pay attention to where the existing gas line is for your application, vs how it's gonna be plumbed into your water... Another reason I only got one tankless installed (wanted 2) was that tank#2 was on the other side of the house and running a gas line all the way there would have cost more. As it is, we had a couple extra "ugly" water lines going up the wall as a result of the tankless (outside wall downstairs, for servicing) feeding the upstairs. No biggie, just info...

I use a gas Navien to supply hot water and slab heat in my detached garage. I don't think id use one for domestic hot water in the house because of the lag. One nice feature is a hot/cold hose bib on the outside of the house. I can refill/heat by hot tub cheaper and faster than ever before, power wash w/ hot water, and run a warm sprinkler for the kids if I want.

Jeff, when you said "scale filter," you mentioned a blue canister. I have a 20 in. x 4 in., 5 micron prefilter (with a blue spin on canister) before my water enters the softening/treatment system for the house. Is that what you were talking about? Also my outside water heater is built into the outside wall between the studs and has a removable panel for access to the heater. Seems like that kind of set up might be an alternative to the attic installation you describe with all the associated mods and expense.

this thing TAC Anti-Scale System for Tankless Water Heaters - FreshWaterSystems.com

usually they are mounted close to the heater, but I suppose it can be mounted anywhere before the water enters the heater.

Thanks for the tip on the heater sitting between the stubs bsy. Personally I think its the nicest solution, but not all heater is that narrow or home are built to accommodate a larger heater. This woman is a real sweet heart but knows exactly what she wants, and are not at all afraid to pay for service. Easy for me, easy for them.