Demand water heater question

[Anna]

Hey, guys,

I spoke to a highly-recommended plumber in town, and he installs and services tankless water heaters. He's coming on Thursday to give me an estimate and see if there are any modifications needed (pipe size, venting, etc). If you have any questions that you think I should ask, let me know. I've been taking notes of online discussions and have a list of questions myself.

I did ask him which heaters he recommends, and he said Noritz immediately. It seems like it's the least trouble with installation and maintenance. He did tell me to stay away from Bosch. Takagi is the other brand I'm interested in because it can go up to ~10 gpm.

HD sells a brand called Paloma, and the gas heater is only $999. I was expecting it to cost more than that. I read somewhere that the 6.5 gpm Noritz wholesales for about ~$600, so I'm expecting to be charged just around $1K for it, too.

I'm also reading something about a recirculator that's supposed to help reduce water waste while waiting for the hot water to come on. I'm going to ask him about that, too.

Anyway, I'll report back here whatever I learn about these things. LOML seems determined to have one installed this year, which is fine by me.

Thanks again for helping me get started on researching this.

[Tom Slick]

My dad has a recirculator in his bathroom, which is on the other side of the house from the water heater. it is an on demand type that you push a button before you want to take a shower, about 1 minute later the water is immediatly hot. no wasted water waiting for the pipes to heat up and hot water to come out of the shower head.

[Anna]

Thanks, Tom. I've been wondering about that. Our bathrooms are on the other side of the house from the heater, and we usually wait at least half a minute to get the water warm for a shower. I think the recirculator might be a good idea whether or not we put in a tankless.

[cgallery]

Anna, it will be interesting to hear what the plumber says. I went through the same routine. I first saw units at HD and saw them on TV, with pricing of approx. $750. I found several plumbers in my area that install them, but the installed price was universally $2000+. The one written quote I received was approx. $2500. I assume they just figured they were the "in" thing and gouging accordingly.

[iceman61]

(I just remembered: When we were living in a place with a much smaller tank, when I got pissed off with my husband, I'd turn the dishwasher on when he went in for his shower. He never could figure out why he didn't get hot water sometimes. It defeated the purpose of "punishing" him, but it's still funny whenever I remember it. I hope he doesn't read this thread.)

You have the wrong idea. What you do is flush the toilet. He gets a surge of hot water & immediately adjusts it. by the time he gets it adjusted the toilet stops filling with cold water & starts to resupply the shower making the shower water immediately take a cold dip. My siblings & I used to do this to each other all the time. Everytime I get in the shower now I ask my 7yr old what he is NOT to do while daddy is in the shower & he will say "don't answer any knocks at the door & don't flush the toilet"

[Anna]

Anna, it will be interesting to hear what the plumber says. I went through the same routine. I first saw units at HD and saw them on TV, with pricing of approx. $750. I found several plumbers in my area that install them, but the installed price was universally $2000+. The one written quote I received was approx. $2500. I assume they just figured they were the "in" thing and gouging accordingly.

David, I'm preparing myself for a price tag of about $2800 because that seems to be the common estimate for these things. Anything less than that will be a bargain from my point of view. This plumber worked for us a few years ago installing one of those closed tank power flush toilets. It cost us about $460 all told (toilet plus install), which I thought was a good price. I'm hoping his pricing for the tankless will be just as good. I'll let you know.

You have the wrong idea. What you do is flush the toilet. He gets a surge of hot water & immediately adjusts it. by the time he gets it adjusted the toilet stops filling with cold water & starts to resupply the shower making the shower water immediately take a cold dip. My siblings & I used to do this to each other all the time. Everytime I get in the shower now I ask my 7yr old what he is NOT to do while daddy is in the shower & he will say "don't answer any knocks at the door & don't flush the toilet"

Too funny and your kid is so cute!

As for flushing the toilet, I didn't want to be overtly vindictive because my husband would have known for a fact I was flushing the toilet to get even with him. With the dishwasher, if he ever figured it out, I could have just claimed I "forgot" he was in the shower. It's called plausible deniability.

[430752]

If you have a boiler, instead of a furnace, consider going with an indirect water heater. It uses the boiler to heat water which goes in a jacket around the water to be used for showers. But, boilers are for old houses. Not sure if you have an old california home, or a new one with a furnace.

As far as tankless, I was going to go that route until I figured the above. Still, the advantgaes of tankless, as I understand it, are both the already mentioned fuel savings, but also the longer life of the unit. Yeah, fuel savings are not immediate, but over the life of a normal direct fired water heater (8-10 years) you'd get the money back, plus the second advantage is that tankless are supposed to last twice as long - to 15-20 years. Not sure if accurate, but since tankless has been used in Europe for many, many years now I assume the claims are mostly accurate where it is not a new technology (maybe only new to the USA).

[leehljp]

From the Japan side . . . We have had and used tankless water heaters for the last 17 years where we live. 14 years in Osaka and 3 years in Toyota. both houses have had three units, one upstairs and two downstairs, located near kitchen /laundry and two bath rooms. One unit had to be replaced before we moved in for the Osaka house. They installed them, tested them, prepared for us to move in and then we had a big freeze. While ours are all gas and located on the outside walls, they have an electric "heaters" in them to keep the water from freezing in cold weather. The installers had accidentally unplugged one and we had a freeze of lower 20's. Busted! That was replaced within a couple of hours of discovery.

These were built with the house. I made up my mind that if I EVER built a house in the States, I would demand tankless. SO much faster hot water than from most hot water tanks that have to serve a wide area.

But it does not seem feasible to convert existing housings. If you install a tankless where an existing tank is then there will be no advantage in wasted water before the hot water arrives. The only advantage is that for continued use, you would not run out of hot water.

Locating them near the water use spots, kitchen, bathrooms, laundry room would require considerable water and gas plumbing or electrical rewiring.

I REALLY like tankless, but it should be designed and installed with the house unless money is not an issue.

[cgallery]

I REALLY like tankless, but it should be designed and installed with the house unless money is not an issue.

Interesting perspective, because in the U.S. (someone correct me if I'm wrong), most new houses that go tankless get a single tankless that supplies the entire house. And the main advantage (that I've seen anyhow) hasn't been the instant hot water, but rather the energy savings gained by not having to heat the water 24/7, but only when you need it.

[leehljp]

Interesting perspective, because in the U.S. (someone correct me if I'm wrong), most new houses that go tankless get a single tankless that supplies the entire house. And the main advantage (that I've seen anyhow) hasn't been the instant hot water, but rather the energy savings gained by not having to heat the water 24/7, but only when you need it.

Now I get it - the US side, that is!

In Japan: It is for water savings here as well as energy savings. Remember that $3.00 and $4.00 a gallon gas has been here (Japan) since we have been here in the mid and late '80s.

By having multiple units, i.e. - near the point of use, it only becomes cost efficient if energy and water costs are high enough to justify it. That is where we have been and where the US is probably headed. Still, to be able to turn on the sink or shower and have hot water coming through within 5 or 6 seconds (OK - by about 10 seconds average) in the middle of the winter sure in nice!

[Anna]

Now I get it - the US side, that is!

In Japan: It is for water savings here as well as energy savings. Remember that $3.00 and $4.00 a gallon gas has been here (Japan) since we have been here in the mid and late '80s.

It's the same way in Europe. I think gas there cost about $6 per gallon when we visited a few years ago, and tankless heaters are just as prevalent as in Japan.

I like the idea of saving both water and energy. I still wonder how much more water we'll be wasting, though, when we're waiting for the hot water to kick in. The master bath is in the far side of the house from the heater, and it takes about a minute of running the water before it warms up. I don't think that'll change much with a tankless, so I'm seriously considering a recirculator to help out.

Installing multiple heaters will cost way too much because of the new plumbing and gas lines. For a new house, though, it probably makes sense to put in a tankless from the outset.

[rnelson0]

A well-insulated water tank does not require a whole lot of runtime to keep water at temperature, similar to a thermos. It's the marginal ones that can getcha. Look at the energy numbers posted on the units for comparison. Consider also a tank "blanket" for additional heat retention. The earlier suggestions are spot-on. It will take a looong time for a break-even, given today's prices for tankless units.

There are downsides to both. The well-insulated water tank *does* run 24/hrs a day, as opposed to the instant heaters - I know it's not a true 24 hours, but if you take a shower at 6am and wash dishes after dinner around 7, that's a lot of time just keeping hot water available with little need. Of course, tankless water heaters can result in scalding if someone takes the cold water away since their temp setting is typically much higher than a regular water heater.

A good compromise I learned in my electrical class is to use a timer on the water heater. Shut it off from 7am-5pm M-F and you'll save a ton of money at a cost of <$100. Unfortunately, I work at home and use the water sporadically through the day, so no savings for me

[Tom Slick]

I have turned off my 40 gallon water heater for several days and had warm water when I returned. It makes me wonder how much I would really save with a tankless. I do live in an area that doesn't get very cold though.

I do think they are the future. Us americans are used to buying cheap appliances and putting up with their ineffeciencies.

[leehljp]

. . . Of course, tankless water heaters can result in scalding if someone takes the cold water away since their temp setting is typically much higher than a regular water heater.

. . . Unfortunately, I work at home and use the water sporadically through the day, so no savings for me

One of the benefits for "on-location tankless" is that it is much less noticeable when water in another place is used. Each tankless unit has a digital setting near the point of use so that it can be set to each individual's preference if desired.

If a person wants to do it, he or she can set the temp to 105°, or what ever is comfortable and not use ANY cold water. At this point, if water pressure drops or is increased, the temp stays the same.

The tankless units we have here - have controllers near the point of use, similar to thermostats for central AC/Heaters, not up in the attic or on the tanks. Adjustability is much easier this way. As to scalding, there is no more danger with tankless than with hot water tanks.

Uuuuhh . . . I don't know how the US tankless units are adjusted, or if they allow for digital thermostat settings in a remote place near the point of use.

One thing that is common here is the wireless remotes for settings in everything, including tankless heaters so that control wiring is a thing of the past.

[rnelson0]

One of the benefits for "on-location tankless"

As you mentioned, hard to retrofit into an existing house. I've got the option of installing a large unit in the basement to replace the water heater, or install 3 or 4 smaller units throughout the house where there is no gas line or electrical wiring - or space. If I could afford it and it would "fit" then I'd do it.