Tankless water heater

[res057]

I'm seriously considering a NG tankless waterheater for my house. The house currently has an electric unit, but there is a gas line stubbed out next to it. It's about 1400 sq ft, no pool or hot tub, 2 full baths. Occupied by two adults, a baby and a dog. Typical water usage. The home is in the southern California desert (pretty warm in winter and blazing hot the other 8 months). It will be installed by a professional, but for now I'm needing any info and input I can get to make an informed decision.
Thanks.

Jack

[PLUMBER RICK]

jack, it's not as simple and inexpensive as it sounds.

a tankless requires a much larger gas line than a normal gas tank style heater. a 50 gallon gas heater is approx. 38-40,000 btu's. a tankless is approx. 190,000 btu's.

if the unit is installed indoors, than a special stainless category 3 vent is required. much less money to install it outdoors ventless.

also a slight delay in getting hot water as the tankless has to start up and come to temperature. approx. 3 seconds longer than tank.

much higher initial cost than a tank. more required maintenance to keep the heat exchanger clean.

as one factory salesman put it "tankless are for tree huggers"

the gas savings are not what they make it out to be.

please do a search on this topic as there is plenty of post both pro and con. i personally don't endorse it for the majority of installations.

question? has your electric heater been an issue? sure it was expensive to operate. gas is much less. gas is a faster recovery. but if you had an ample supply of hot water, then a tank heater is a much better upgrade than a electric tank heater.

there are some that will disagree with me, but my personal experience and knowledge of the product has kept me from installing a tankless at my own house.

rick.

[res057]

Rick,
Thanks for the info. If I get it, it will be an outside install. The water heater is working fine so far, but is pretty old and the electricity in Cal. (as you are well aware!) is expensive. The chief financial officer(wife) blows a gasket with each electric bill (thankfully, we are on IID and not Edison).
Replies like yours are the reason I like this forum over all the others I've been on.
Thanks.

[Australian Plumber Josh]

my two cents.

Yes, gas line needs to be correctly sized, and outdoor install much simpler.

Tankless promoted heavily here in australia and gaining poularity with consumers.

There is no saving on gas bills between a storage type and tankless in my experience. In fact i think my gas bill increased, but mainly due to teenage daughters finding everlasting hot water much to their liking.

Water consumption has also increased for the above reason.

Also tankless heaters have a minimum flow rate before they run properly, and any flow restricting type shower haeds etc can play havoc.

The ignition on the heater is electric so despite it being a gas heater you will still have no hot water without electricity.

Overall they do the job fine. My decision to install was partly based on restricted space available.

Josh

[cactusman]

Is there a comparison chart someplace regarding the four types of water heating?

1. electric 50gal tank
2. gas 50 gal tank
3. solar hot water with 50 gal tank
4. tank-less hot water gas fired

I would think it could be a very interesting chart comparing:

1. installation cost
2. operating cost
3. product cost
4. longevity
5. length of time for payback
6. utility expense
7. any energy rebates offered
8. maintenance
9. etc.

Cactus Man

[res057]

That's a great idea Cactusman. I'd like to see that too.

[plumberscrack]

For all you non believers in tankless heaters please pull yourselves away from the Ridgid forum for 10 mins and go here http://www.foreverhotwater.com/index.php
The Rinnai has by far the best product and selection of tankless out there.

This site also has all the comparision charts Catusman mentioned and Tax Credit savings.

Now I don't know how often or the lenth of time that some of you lose electricity but needing hot water when the power is out is a weak arguement against tankless.

[westcoastplumber]

I have installed plenty of Rinnai Tankless units. Couple things to keep in mind:

Bring in gas from the meter

Bring in water from the main to guarentee needed flow rate, do not reduce piping size until you are at the unit. ex: 1" water main enters the house, keep 1" to the unit, reduce down at the unit.

Hard pipe everything in, water, gas etc. No flex lines. Make sure your plumber installs by pass valves to service unit.

Downside: Re-circ pumps need to be supplied off a 6 gallon water heater, not off the unit, if a re-circ pump is run off the tankless unit, it will shorten or void the warrenty.

Downside: Yearly Maint program, a plumber needs to come out and run vinager in heat coil to remove build up from hard water. (recommended)

Don't forget the dedicated 110 v waterproof outlet, have electrician install a switch at the unit so when it needs to be serviced, it isn't an inconvenience.

Very few plumbers install these units int he correct way. The only complaints I have recieved about these units are caused by improper installation.

Highly recommend Rinnai.

[wwsmith]

I have been following this thread with some curiosity as my neighbor is currently building a new home next to mine and I have enjoyed learning various things by watching on occassion as well as reading various things on this forum. :)


Hard pipe everything in, water, gas etc. No flex lines.

I am curious about this comment though? Any particular reason one couldn't or shouldn't use Pex? I noticed that is what appears to be prepped in his basement (he is also going to use a tankless, but I am not aware of what kind/brand). His house is being plumbed similar to mine in that everything is 3/4" or 1/2" Pex (3/4" main in copper from the city comes in from 16 feet below street level to the basements). Only other copper or hard pipe is where the fixtures are stubbed out. In the case of gas it is hard pipe from the meter to the basement where it stubbs off of a type of manifold to that yellow flex to each individual appliance that uses gas in the home (i.e. water heater, furnace, fireplace). Same with my own home.

Always curious....:confused:

[PLUMBER RICK]

I have installed plenty of Rinnai Tankless units. Couple things to keep in mind:

Bring in gas from the meter

Bring in water from the main to guarentee needed flow rate, do not reduce piping size until you are at the unit. ex: 1" water main enters the house, keep 1" to the unit, reduce down at the unit.

Hard pipe everything in, water, gas etc. No flex lines. Make sure your plumber installs by pass valves to service unit.

Downside: Re-circ pumps need to be supplied off a 6 gallon water heater, not off the unit, if a re-circ pump is run off the tankless unit, it will shorten or void the warrenty.

Downside: Yearly Maint program, a plumber needs to come out and run vinager in heat coil to remove build up from hard water. (recommended)

Don't forget the dedicated 110 v waterproof outlet, have electrician install a switch at the unit so when it needs to be serviced, it isn't an inconvenience.

Very few plumbers install these units int he correct way. The only complaints I have recieved about these units are caused by improper installation.

Highly recommend Rinnai.

very good grasshopper:D you do your's right. problem is most don't do it right. when you add up all the extras and possibly the vent pipe, the payback is not there.

the electric heater he has is very costly to run. a gas tank heater is very economical to install and maintain. a tankless is very expensive to install and maintain on a regular basis.

don't see anyway to offset the cost between the tank and tankless.

it's probably 2.5- 3.5 times more expensive to purchase and install than a tank. all the savings in the world will not recoup the outlay of cost and maintenance.

since he doesn't already have gas or a vent, there are possibly some cost that will be similar. a 1/2'' gas line upgraded to a 3/4''- 1'' line are not that much, unless he has a long distance to run. a stainless vent is real expensive if he needs to run it.

the gas savings is peanuts out here. annual service of the heat exchanger will wash any savings down the drain. my 18 year old heater is still going strong and all i do is run 15 seconds of water out the drain 2 x a year.

still not a believer in cost savings:confused:

but a believer in your ability to do the job right:)

rick.

[plumberscrack]

Robert,
grab a Rinnai and take it over to Rick's and install it. He's obviously not going to do it himself. He will love you for it :D

Rick,
"tree hugging" is a good thing :D

[westcoastplumber]

Yeah, I wasn't getting into the cost issue. Everything comes at a cost, if you want endless hot water, it comes at a cost. I understand he has an electric water heater, he needs to get ride of that either way he goes. Personal needs I leave up to the customer, I just wanted to make sure that when he gets his estimate, all the above things are included in it so he guarentees the job is completed right. since the unit is exterior, he dosen't need a vent, he just needs to go with the exterior model, he will save on the vent cost. depends on him and his preferences and what he wants to spend.

[westcoastplumber]

I have been following this thread with some curiosity as my neighbor is currently building a new home next to mine and I have enjoyed learning various things by watching on occassion as well as reading various things on this forum. :)



I am curious about this comment though? Any particular reason one couldn't or shouldn't use Pex? I noticed that is what appears to be prepped in his basement (he is also going to use a tankless, but I am not aware of what kind/brand). His house is being plumbed similar to mine in that everything is 3/4" or 1/2" Pex (3/4" main in copper from the city comes in from 16 feet below street level to the basements). Only other copper or hard pipe is where the fixtures are stubbed out. In the case of gas it is hard pipe from the meter to the basement where it stubbs off of a type of manifold to that yellow flex to each individual appliance that uses gas in the home (i.e. water heater, furnace, fireplace). Same with my own home.

Always curious....:confused:

we are not allowed to use pex here in los angeles, I have nothing against pex, except for the potential loss of heat and coldness, and the possibility of it getting ripped apart by a rodent, other then that, it is easy and fast to install and asl ong as it is wirsbo or rehau, it is good quality. I mean't the corrigated gas and water flex, it is a crappy cheap way to install a tankless. To the gas appliances, corrigated is fine, IPC says ridgid copper has to run to the fixtures a certain distance before it terminates the wall, hence the copper stub outs.

[ToUtahNow]

Oddly enough I sat through a Rinnai seminar the other day and the Rennai Rep spent most of the time explaining the down side of tankless heaters. The 30% saving on my gas bill would take a really long time to recoup the cost of the tankless. Then add in that I have a circulating system and the savings drop to 15%. If I was building a new home I would likely go tankless but not as a replacement.

Mark

[res057]

Thank you everybody for your input. My decision has been made. Stick to the old style (but change over to gas). If new constructrion, I'd probably be all over it. But seems a retrofit would be a waste of resources (time and money, but mostly money). Not planning on keeping this house long enough for any financial returns to come about.
I hope this thread has helped someone else as well.

[PLUMBER RICK]

Oddly enough I sat through a Rinnai seminar the other day and the Rennai Rep spent most of the time explaining the down side of tankless heaters. The 30% saving on my gas bill would take a really long time to recoup the cost of the tankless. Then add in that I have a circulating system and the savings drop to 15%. If I was building a new home I would likely go tankless but not as a replacement.

Mark

mark, 30% sounds way too high. even at 30% that would only pan out to $4.50 a month for me. at approx. a $1500- 2500 additional cost for the heater and additional work, i don't think any of us would live long enough to recoup the money. not to mention the additional maintenance cost to keep the heat exchanger clean.

i like the fact of endless hot water, but i haven't a need for it. also endless is typically maxed out at 8 gallons per minute and that's with a 40 degree rise. in the cold country, it falls way off.

mark is it just us old timers (you, i, and steve) that see the light:confused:

i agree that a tankless has it's place under certain circumstances, but it doesn't apply for 99% of my customers and myself.

glad we can spot the snake oil salesmen. like one salesman told me. it's for the "tree huggers"

rick.

well i guess i was posting while the decision has been made. another satisfied customer

[Australian Plumber Josh]

I use these Zetco valves for tankless installation.

Valve has nut and tail, available for flared or threaded connection.

http://www.zetco.com.au/content/view/75/59/

http://www.zetco.com.au/content/view/73/59/

Makes things simple for me.

Im unsure whether they can be used in north america.

Josh

[plumberscrack]

Thank you everybody for your input. My decision has been made. Stick to the old style (but change over to gas).

Lost another one :(

When you "old timers" wake up to the 21st. century let me know :p

[ToUtahNow]

Rick,

The 30% savings were Rinnai's numbers not mine. I think the savings will be different for everyone depending on their demand. The sad part was one of the plumbers left the seminar pissed off because he said he had attend to be sold on tankless not discouraged. The Rep simply replied they have to make too many service calls where they have to explain why the tankless was not living up to the plumber's promise.

I am sure I will go tankless someday but it will not be because it saves money.

Mark

[PLUMBER RICK]

Lost another one :(

When you "old timers" wake up to the 21st. century let me know :p

crack, if anyone invest in new technology, it's me.

i owned a seesnake prior to ridgid, trenchless, t-drills, pipe freezing, propress, ect, ect, ect.

but if i'm going to invest in new products, they have to show positive results.

all the tankless proves to me is it cost more to buy and operate.

i've repaired/ reworked more tankless installations in the last few years, than 30 years of tank heaters.

even bought a tankless for my own home. it's still sitting in the box waiting for my 18 year old faithful tank heater to pass:eek:

someday the old timers can show the youngsters a thing or two:D

show me the numbers between a tank installation and a tankless. show me the savings:rolleyes:

looks too much like a domestic solar system payback.

rick.

[DuckButter]

I've done a lil' over half dozen in the past year and inquiries have gotten more frequent with time.
I find there are major differences in different models.
One in particular, the Bosch, I don't recommend (sold cheap at Lowes...purchased by customer prior to calling me) it shifts wildly in temp for a good minute after turning it on.
The math is simple...tank types are 60-65% efficient, tankless are 80%+ when on, BUT 4 times the BTU to heat the water quickly enough. (relative math...uses the same energy per gallon of water, but 20% more efficient)
IF you get a request for a cheaper single bath model...shy away...they have serious flow restriction...designed to slow water flow when demand exeeds it's ability to heat to the set temperature.
One BIG note, I'm hearing heavy mineral/hard water can be torture on the exchangers, some of the warranties make a note in fine print that the warranty can be void in higher concentrations in the water supply.