TANKLESS WATER HEATERS

[Todd]

Any comments or recommendations on gas tankless water heaters? I hear they use less energy but cost more. Are they worth it?
Do they deliver hot water quicker? I might be needing a new heater soon, old one is acting up and is over 10 years old.

 

[RoosterBoy]

todd I'm glad to see that your thinking about saving energy and yes a thankless is the way to go if you want to save allot of gas or oil on hotwater try to put it in the center of all your hot water needs so you ll get hotwater at the tap fast.

thanks
Jason

 

[elkimmeg]

Rooster care to hazzard a guess why his only lasted 10 years. What you think builder's special hed did not mention the menufacturer or BTU requirements

 

[KP Matt]

I had tankless water heaters in my apartments in Spain and Taiwan. I never had a problem with them. Except that they used tanks of butane and that you had to call to get more delivered when you run out. I imagine that problem has been overcome. In North America I've never seen motorcycles with three giant tanks of butane strapped onto the rack careening through intersections and the driver with a butt hanging out his mouth.

One thing I recall is that in both countries those units were always located outside the living space - in the building's interior shaft.

 

[EatenByLimestone]

I've heard of people having to upgrade the incomming NG line to a larger diameter due to the much higher fuel demand. This would add greatly to the cost, you may want to find out if yours is large enough.

 

[PAJerry]

We've been using a tankless water heater since 1983 - Paloma Model ph-12, natural gas - and I would never go back to a tank. We raised 3 kids, which meant LOTS of laundry and showers and it never failed us. No one ever ran out of hot water. A new unit costs about $450 and is worth every penny. I have the unit tucked in under my basement steps and vented out the chimney just like you would a tank, but it hangs on the wall and takes up very little space. The only maintenance issue I had with ours was that I had to replace a small ignition baffle due to some sediment in the water when we brought a new well on line. 15 minute job and a $5.00 part.

In my opinion, a tank type water heater is a real energy waster, especially if there are only 2 people in the house like we are now. It's like leaving the coffee pot on 24 hours for 1 cup of coffee or letting your car idle in the driveway all day and making one 2 mile trip to the store. Think about it. Nearly all of the rest of the world uses tankless water heaters so there must be good reason.

 

[Todd]

Thanks for the replys guys. Looks like a tankless can last up to 20 years compared to 10-15 for a tank type. But the difference in unit cost plus installation probably won't make my money back. I'll have to give some local plumbers a call and see what they have to say.

 

[cbrodsky]

The only way I see that these really pay off is if you have them right next to all of your water outlets.

In our house, we have bedrooms with bathrooms that are spread apart so the biggest source of loss for us is the fact that when you need hot water, you have to first fill all the piping running from the central boiler to the point of use. When you're done, the volume of water in those pipes ends up just cooling down and you lose the heat in 1-2 gallons of water. And you incur this loss every time you ask for hot water after a delay of an hour or two during which the pipes cool down again.

The other issue of losing heat from your hot water tank while it sits there is easy to overcome. The price difference in a tankless heater will pay for a LOT of heavy insulation on a water heater. I don't think that is really a significant difference once you add some insulation to the tank.

So my take would be if the tankless device is small enough that you can locate it much closer to your point of use than your traditional water heater, it's probably a good move. But if not, there's no sound reason you will save any money - don't get sucked into hype. Look at solar instead. We know that we can't locate multiple tankless units near all our points of use so we are going that route as an even greener alternative that makes more financial sense for our situation.

BTW, as for overseas use, in small living quarters it makes sense purely for space reasons.

-Colin

 

[begreen]

The summary is good. Note that the delay getting hot water out of the tap is often a design issue and one common to central tank hot water systems as well. Often abroad it's typical to have multiple local systems. We had 3 in our apt. in India. One for each bath and one for the kitchen. They call them geysers and were electric, so one had to turn it on about 15-30 minutes prior to use, but there was always enough hot water. In Mexico and some parts of France we had gas units, again most frequently at the point of use unless the place was pretty tiny. I think electric was prefered in India due to risk of poor installation in cramped quarters. There have been deaths reported due to CO poisoning.

 

[RoosterBoy]

Rooster care to hazard a guess why his only lasted 10 years. What you think builder's special hed did not mention the manufacturer or BTU requirements

Lot's of reasons a hot-water could fail early #1 if he keep-ed the temperature in the tank real hot that will promote scale build up
also hard water is bad for tanks anodised rods. also not sure what he has if it's a indirect hot-water then it should have lasted a little long but then again it depends.

if it's electric the changing the Col's and rods and a good cleaning and checking his water for hard. may bring it back to life
i am no hot-water heater expert i just know how to install them. and im just telling you what i have seen

but most of the time cheep hot-water tanks last about that long ;-) if i was him id get a tank-less put it in the center of where all his hot-water use will be and he will enjoy the savings and the unlimited amount of hot water.

thanks
Jason

 

[KP Matt]

Another small reason why they're more popular in warmer countries - if your climate is cold enough to need a woodstove, then for at least half the year the heat that a hotwater tank loses is not wasted. In warmer countries a hotwater tank is radiating unwanted heat most of the year.

 

[Todd]

Rooster care to hazard a guess why his only lasted 10 years. What you think builder's special hed did not mention the manufacturer or BTU requirements

Lot's of reasons a hot-water could fail early #1 if he keep-ed the temperature in the tank real hot that will promote scale build up
also hard water is bad for tanks anodised rods. also not sure what he has if it's a indirect hot-water then it should have lasted a little long but then again it depends.

if it's electric the changing the Col's and rods and a good cleaning and checking his water for hard. may bring it back to life
i am no hot-water heater expert i just know how to install them. and im just telling you what i have seen

but most of the time cheep hot-water tanks last about that long ;-) if i was him id get a tank-less put it in the center of where all his hot-water use will be and he will enjoy the savings and the unlimited amount of hot water.

thanks
Jason

Family of 4, Richmond 40 gal, 40,000 btu gas heater, tank is set at medium. I have well water with high iron, water softener and carbon filter, I removed the anode rod 3 years ago, was told it would help with the egg smell. Also drain it every year and have never seen any sludge or deposits come out. Last couple days the hot water seems fine.

 

[Rhone]

I think I can give a pretty good comparison if you're referring to tankless vs. tanked instead of on-demand vs. tanked.

Tankless models hold around 3 gallons or so of water and maintaining it at 120 or whatever you set the temp at. So, a tankless model still idles when you're not using water, but maintaining 3 gallons instead of 40+ is better. I have a Peerless boiler with a Beckett pump that's tankless for a family of 2, my parents also have a Peerless boiler with a Beckett pump and family of 2 except theres is configured with an 80 gallon tank. We both burn wood for heat. I had a problem that wasted 75 gallons of oil and ended up using 331 gallons for the year. My father went through 330 without problems so the tankless is better, I should have used only 256. I also used my tankless to heat my house for half of fall and spring my father didn't. I think we both use the same amount of hot water. That's around $187 in savings for the year.

You can do some things with tankless you can't with a tank if you want to risk some wear & tear on it. My tankless will be fully hot in 7 minutes after turning on. I turn mine on/off freely as if on-demand, usually turning it on when I get up and my wife & I take our showers then we shut it off. If at night, we turn it on, let it warm up the water and shut it off. That creates enough hot water for up to 4 hours of washing hands, etc. The problem with on/off is the gaskets are expanding/contracting and getting wear but I can't see how that process puts any more wear & tear than a tanked system. This next is hard to explain. I basically heat my house for free while we take our showers. In winter, I have to turn it up to 170-190. Waking up and turning the boiler on in winter, it's ready after 7 minutes but stays on heating the water the entire time I, or my wife are taking a shower trying to get the water to 190. Instead, we turn on the boiler, turn on the heating system, in about 8 minutes it's hot enough for our showers and while we take a shower it's now heating the water we're using and heating our house at the same time. After we're done, we go up there and shut it off along with the heating system. That's a hard one to explain, basically instead of wasting the oil used to heat the water beyond 120F when taking our showers in winter, we're using it to heat our house instead. One wastes the energy, the other uses it.

So, I think there's an improvement but very hard to say exactly how much because there are differences. I have insulation on all the pipes within 6' of my boiler my father does not. I can shut my boiler off when not in use with little consequence, my father can not. My fathers shower is approx 30 feet away from his boiler, mine is 10 ft. My wife uses more hot water than probably all the others discussed combined, to offset her I do things much colder than all to probably be pretty close in the end. I use mine for heating in parts of spring & fall, my father does not. Anyway, with all the pluses & minuses I think a tankless system is 10-20% improvement over a tanked and I happen to probably get 20-25% because I take full advantage of the tricks a tankless system offers that a tanked system can't... but to the detriment it adds more wear & tear.

 

[the_guad]

Don't forget that with an ondemand tankless system you may need more than 1 depending on your peak hot water usage. I was going to get 2 but didn't have the electrical capacity and ended up going back to a standard tank. You need a couple hundred free amps for the electric models and I think 2 free circuit slots.

In short, I would have gone tankless if I could have.

 

[jabush]

Thanks for the replys guys. Looks like a tankless can last up to 20 years compared to 10-15 for a tank type. But the difference in unit cost plus installation probably won't make my money back. I'll have to give some local plumbers a call and see what they have to say.

A buddy of mine is going with an (electric) on demand system, but he is installing it in-line above his existing 50 gal tank. That way he has a supply of water that's at room temp instead of heating 50 degree well water. That might be worth a look if you have room and your current tank isn't leaking.

 

[saichele]

The tanked water heaters aren't necessarily energy hogs. i got a mid-grade 50 gal shorty at lowes 2 yrs ago (about $300) and wrapped it in a foil backed fiberglass blanket. And we keep it pretty low (about 115F). But it'd big enough to fill the tub or take a shower and so on with mostly hot water (as opposed to mixing) and the relatively low gradient to the basement air temp, combined with the thick blanket, keeps gas use down to about 20 ccf/month.

We go through about 12000 gallons of water a month, maybe 1/4 is hot, so 3000 gallons. About 25000 lbs. Heating that from 55 to 115 requires 60 * 25000 = 1,500,000 btus, and we use about 20 ccf/month (some of the gas is cooking, but lets ignore that). 1.5 MBTU required / 2.0M BTU used - So it's not super efficiency, but >75%. I bet if it were sitting thee at 150F all the time it would be a lot more, even though we use less water.

Steve

 

[BrotherBart]

I know. I watch these water heater discussions with great interest. My three hundred buck electric water heater set at 120 and wrapped in fiberglass blanket puts out everything we need, when we need it, and if the A/C ain't running the electric bill is $80 a month. I can't see any payback to the exotic stuff, much less heating water with oil or gas.

 

[Rhone]

Hey, you peaked my curiosity to see if a higher costing oil boiler gives you a payback over choosing the low cost electric tank but higher cost of electricity. In my area, a 92% efficient condensing oil boiler will run $5000 including installation. Although they say 92% I'm using 82% because you know how those efficiency things go. Will I ever recoup my $ choosing it over a $300 water tank & extra insulation but higher cost of electricity?

I found out where I live it would be wiser to pay for the boiler, oil, and maintenance/year I'd start pulling ahead with the boiler system after the 4th year and at the 15 year mark I'll be around $10k the richer. Not to say it will apply to anyone else, where I live electricity is off the charts and every dollar I spend in oil I have to pay $2.66 to do the same using electricity. This makes me think of my future, as next year I plan on switching over to a solar domestic hot water system with electric backup. Electricity costs so much I may be better off keeping my oil boiler and using it as the backup instead of paying for electric backup to my water tanks (I'm planning on 3 tanks).

 

[saichele]

Sure, and if you're using the boiler for heat anyway, it all makes sense. We have GFA heat, so no help there.

Inthe shoulder seasons, our combined gas and electric runs about $80. Last couple months more like 150. Winter a little over $100, but burning 100/mo in wood.

Steve

 

[Sandor]

I think doing calculations based on today's energy rates is a bit misleading when doing cost analysis.

I would add about 5-10 percent year after year to oil/gas/electric costs as a ballpark when doing forward calculations for payback.

I really don't do the analysis any longer, I just buy the most effiecient anything I can.

Glad I left Maryland, most electric rates in that state increased 30-60 percent due to deregulation restrictions ending. Talked to my mom in MD yesterday, and they got wacked with a 30% increase.

 

[jabush]

I think doing calculations based on today's energy rates is a bit misleading when doing cost analysis.

I would add about 5-10 percent year after year to oil/gas/electric costs as a ballpark when doing forward calculations for payback.

I really don't do the analysis any longer, I just buy the most effiecient anything I can.

Glad I left Maryland, most electric rates in that state increased 30-60 percent due to deregulation restrictions ending. Talked to my mom in MD yesterday, and they got wacked with a 30% increase.

Actually it was more like a 17 percent increase (July 1st) this year for BGE customers in MD. Next year they will get us with the rest of the hike, which will be another 55 percent. Either way it sucks!!

 

[Sandor]

I think doing calculations based on today's energy rates is a bit misleading when doing cost analysis.

I would add about 5-10 percent year after year to oil/gas/electric costs as a ballpark when doing forward calculations for payback.

I really don't do the analysis any longer, I just buy the most effiecient anything I can.

Glad I left Maryland, most electric rates in that state increased 30-60 percent due to deregulation restrictions ending. Talked to my mom in MD yesterday, and they got wacked with a 30% increase.

Actually it was more like a 17 percent increase (July 1st) this year for BGE customers in MD. Next year they will get us with the rest of the hike, which will be another 55 percent. Either way it sucks!!

Yep. My mom has SMECO - Southern MD Electric Cooperative. Maybe there is more on the way for her.

 

[jabush]

I think doing calculations based on today's energy rates is a bit misleading when doing cost analysis.

I would add about 5-10 percent year after year to oil/gas/electric costs as a ballpark when doing forward calculations for payback.

I really don't do the analysis any longer, I just buy the most effiecient anything I can.

Glad I left Maryland, most electric rates in that state increased 30-60 percent due to deregulation restrictions ending. Talked to my mom in MD yesterday, and they got wacked with a 30% increase.

Actually it was more like a 17 percent increase (July 1st) this year for BGE customers in MD. Next year they will get us with the rest of the hike, which will be another 55 percent. Either way it sucks!!

Yep. My mom has SMECO - Southern MD Electric Cooperative. Maybe there is more on the way for her.

Sorry...I assumed (wrongly) that she was a BGE customer. I think the other utilities in MD have been increasing their rates all along, but BGE people will take huge hit over the next couple years.

I think I'll insulate my water heater soon.

 

[Sandor]

I think doing calculations based on today's energy rates is a bit misleading when doing cost analysis.

I would add about 5-10 percent year after year to oil/gas/electric costs as a ballpark when doing forward calculations for payback.

I really don't do the analysis any longer, I just buy the most effiecient anything I can.

Glad I left Maryland, most electric rates in that state increased 30-60 percent due to deregulation restrictions ending. Talked to my mom in MD yesterday, and they got wacked with a 30% increase.

Actually it was more like a 17 percent increase (July 1st) this year for BGE customers in MD. Next year they will get us with the rest of the hike, which will be another 55 percent. Either way it sucks!!

Yep. My mom has SMECO - Southern MD Electric Cooperative. Maybe there is more on the way for her.

Sorry...I assumed (wrongly) that she was a BGE customer. I think the other utilities in MD have been increasing their rates all along, but BGE people will take huge hit over the next couple years.

I think I'll insulate my water heater soon.

I used to work in Baltimore City and you should have seen the line of trash trucks heading in to the BGE generating plant of of 95!

So, your paying money to have Baltimore City and County burn their trash!

 

[richg]

I replaced my electric tank with a Bosch tankless. It has dropped our electric bill by $50.00 per month.