I currently own a 2 family house, in which both units have a 30 gallon water heater.
Do the tankless water heaters really save you money?
Are they better than the reg water heaters?
Is it worth to switch to tankless?
I looked at the tankless option a few years ago and found that it would take about 10 years to get the money back that it might save. So, I just went for the normal kind. Now, with gas prices higher you might get that money back faster, and if you have a problem running out of hot water then it is a good deal.
Make sure that you look at the ratings on the units and what your cold water temperature is. The tankless heaters only get one chance to make the water hot enough, and depending on your demand and how cold your water is it might not do it.
Many units have a much higher input than a standard tank-style heater. Have a plumber check the input against the existing house line size. You may have to convert to 2psig gas delivery or increse the size of the gas line inside the house.
The on-demand water heaters are also sesitive to water pressure. If you have too little pressure, an on-demand heater won't work properly.
Savings? Depends on consumption. Generally, the range is around 20-25% or so but mainly the saving reflects elimination of the stand-by energy loss that all tank style water heaters use.
Do a search on this site- we have had good discussions in the past on a number of occasions. As with anything, beware of 'savings' proposed. Also, one person claimed in a past discussion that the tankless units would outlast a standard water heater 2:1. With all those moving parts, technology, high head heat exchangers, etc.... I'll take him up on that bet anytime and I am personally opposed to gambling, generally. There are many claims; some true, some sort of true, some not true at all. Your mileage will vary, no matter what choice is made. They can be a life (energy, really) saver for some users, inconvenient for some and others may never realize pay off in savings.
Don't confuse me with facts, my mind is already made up.
Just went down this road, so here is the bottom line in my opinion. Cost up front is considerabley more, savings on running one compared to the newer tank style, about 20%. Anuual cost on running a NEW 50 gallon @.91 cents a therm, $231.00 a year. So savings for a year on a tankless, $46.00 yearly or $3.83 a month. If you have a need for unlimited hot water, then it surely is the way to go. If you have enough hot water currently, the savings just don't justify it. You will need to consider what all you will have to change to install a tankless. You will need a larger gas line, typically a 3/4", you will have to change your flue for direct vent applications. A newer tank style hot water heater will drop right into place of your old one, a tankless will require a completely different installation. A good tankless will have about 236,000 btu output, so make sure of your venting and gas supply before even considering one. There are also complaints about the water running hot, then cold, if the flow rate isn't high enough. I would only remotely consider one if I was constantly running out of hot water, and since I have three girls in my house, this is a reality for me. And I still just installed a NEW tank style natural gas water heater, AFTER I did all the research. By the way--the NORITZ N-084 is what I'd choose to purchase.
If you are having trouble in one area you may consider adding one for "point of use" needs not whole house. Several years ago I installed gas meters in small townhouse building, I think 5 units and they were equipped with instantaneous units. About a year later they were all changed out to conventional tank type.. I'm sure newer one should be better, as long as sized properly
I thing that convince me to pass was that I was told these tankless heaters may need periodic chemical cleaning of the heat exchanger.
As one post said- a whole lot of technology and moving parts to fail.
I have a Takagi tankless heater (The 185KBTU model, TKD20 or whatever) that has been operating since the spring. I chose this after a long search.
I installed it not to save mony, but to provide space heating (600 sq. ft floor heat, plus my shop) and to be able to provide endless hotwater, such as for filling the whirlpool.
I was very surpised to find that I used about 50% of the therms during the off-heating season. The gas company provides a graph of consumption with the bill. My old WH was a gas Rheem, open combustion, apprx. 60% efficient. As I recall my new tankless unit is about 85%. Domestic hot water usage tends to be very consistent in households, especially over this time frame.
I chose this model due to: The company has been making them for a long time (made in Japan), and also it is one of the few (besides the one Paul Harvey promotes) that has an outside air intake. It also has an electronic front panel remote that shows: water temp in / out, gallons per minute. This is very handy information when you are running circulator pumps (two).
*What I like about it: Plenty of capacity, never run out of water. ALMOST SILENT ! !. Small, mount on the wall.
*Disadvantages: Washing hands is the big one. The delay is annoying. For bathing/heating, everything else: wonderful
Also, your gas line may get maxed out (mentioned by a previous poster). I am fairly close, I could add a gas range and then I would be at the upper limit, be sure to check with your gas company.
Also, I am skeptical too about the longevity claims. When you open the cover the box is literally stuffed full of parts.
The upfront cost is expensive (2-3X)
Note that I have 6-7 months all like this. The old water heater was in good repair, with a recent cleaning. If anything, we took longer showers...
This is the July bill.
[Edited by steel butcher on 12-02-2005 at 11:40 AM]
Thankless is nice if you do not have room for a tank. The burner will need to come on to meet demand. But I like the storage tank type because you can set the programmable controls say like on the Amtrol, to only heat the water if the burner is already calling for heat or you can set it up to tell the burner to come on if you need the heat to heat the water. You can also set up a nice differential temp or ask the burner to warm up before asking the circulator to come on. They have lots of options and in the summer the tank warms up the one time in the morning and keeps the heat all day. You can set it up to save money or to have convenience.
Every one will have an opinion and that is my 2 cents.