Gas water heater or water-on-demand heater?

The on demand water heaters initially cost about triple a regular unit. They may be installed indoors or outdoors, to be located closer to the demand for hot waqter.

I've used natural gas water heaters all my life, because (as you know) they are the most common. About 5 years ago my brother and I were remodeling a house and decided that the gas water heater was taking up too much space. We weren't sure how good an electric water heater would work. My initial thought was that it can't be as good or people would use them more than gas. After we installed it, I come to find that they work VERY good. Everyone that used the shower really liked the fact that they could take a shower as long as they wished, without running out of hot water. It really comes in handy if you have several people waiting in line to use the shower or if someone in the house wants to do laundry or dishes while you're showering. You literally have an endless supply of hot. As for the cost to operate, I'm not personally sure. I think companies who sell electrical water heaters claim they don't cost much to operate because they're only on when you need them (unlike a gas water heater). I would imagine that electric water heaters could be safer but I'm not sure. I say that because gas water heaters can explode if something goes wrong AND the pressure relief valvue doesn't work. The last good point about electrical water heaters is that they take up far less space. You can mount it on an outside wall and use the space inside for something else. As a side benefit, they usually come with a thermostat, so you can adjust the water to the exact temperature you want. In short, I think the electric water heater is better.

A tankless water heater would save gas, but there are some caveats that affect installation costs, most of which have to do with the location of the heater. Although they use less gas in the long run, they need a large gas supply for proper operation. With propane, this could be accomplished with regulators (running medium pressure to the heater & regulating down at that point). Venting is another issue, as TWHs do not use a standard vent. If you're in a warm climate and can mount the heater outside, it's not an issue. If the heater can be installed near an exterior wall, it's less of an issue. Balance that with locating the heater close to the plumbing fixtures (to avoid long waits for hot water).

The best people to ask about this are the manufacturers. Noritz, Takagi and Rinnai are the big three.

I am not sure what kind of "plumber" Laura talked to, but she was definitely misinformed. Normally they are sized for whatever temperature rise is needed to achieve a 120 degree water temperature during the winter when the water temperature is the coldest. For example, here in the midwest, we size it for an incoming water temperature of 40 deg. So I would determine what flow rate is necessary to get a 80 degree temperature rise based on peak demand in gallons per minute. I would select a heater that had a sufficient flow rate at a temperature rise of 80 degrees. They have no problem reaching that temperature.

The amount of propane you use is going to depend a lot on how much hot water you use and the combustion efficiency of the heater. The tankless models only heat the water you use so the cost will be less than it is now.

There are several things that need to be taken into consideration when upgrading to tankless. First, the unit needs to be mounted on a wall and water and gas lines need to be re-routed to the new unit. Also, depending on the heating capacity, the gas line may need to be upgraded from 1/2 to 3/4 inch pipe. They require a standard 120 volt outlet for power, so if one is not nearby, that would need to be added. Lastly, the heater needs to be vented with either stainless steel or PVC pipe, depending on the model, through the side wall of your house.

Tankless water heaters cost more to buy and are more expensive to install than the regular tank-type. Sometimes it is simpler (and cheaper) to install under-the-counter, electric on-demand, tankless units at the sinks, wash clothes with cold water, and leave the water heaters on pilot flame only and then when needed turn the burners to on. Or see if electric water heaters would be cheaper?

It's a big hassle any way you turn, but excessive propane pricing has made it that way. My son, lives in Michigan, was so upset about propane costs that he bought an outside, wood-burning boiler that provided heat (and hot water) to his home. Fortunately for him, he has 17 acres of woods to draw on for fuel. His house is so hot now that I can't stand to visit him in the winter and, according to him, he has plenty of hot water.......

P.S. Because your propane bills are so outrageous, if you were to install a similar wood-burning boiler, it would be cheaper for you - even if you had to buy your wood..........In the long run you would come out way ahead, providing, of course, that you could afford the initial purchase? Payout would be fairly quick..

300 dollars a month. You have to be kidding.I have a 2000 sq. ft. house and i don't pay that much to run the furnace, water heater,and stove.I pay around 2$ a gallon for propane.

Tankless heaters are more effiecient but cost a lot more to install.They make good ones now that will work in most applications.THe only ones worth using are Nat. gas/ Propane models .Electric's are way too expensive to use.

Do you want to save money or energy.Can't do both.

How much do you pay for propane?

I don't believe there are any savings in a tankless water heater for your application.

They are used more for high demand hot water usage.

Watch the video at this link. Hope this helps. Tom

http://www.consumerreports.org/cro/appliances/heat...

Also if your system is using a circulation pump to have your hot water at the faucet in a couple of seconds after you turn it on that will run your bill up. Look into that. Some new homes use it and it can easily disabled.

I just talked to a plumber about installing one. He said that they definitely had their uses but he didn't recommend them for a whole house application because of their temperature differential. Each unit only heats water by 30 degrees. So here in the northeast, you would need two back to back to get the water just warm, not even hot, which would be about a $6500 install cost.

Now if you're in a warm climate then this may not be a problem for you. This is a good article that talks about the temperature differential under a table sorted by average groundwater temperature, http://ce.construction.com/article.php?L=134&C=438...

Alternatively, are you just able to set one of your tanks to a vacation setting except when you're using it?

Edit/Update: If Jim D has one, that's great. I'm glad it's working for him. But the link I included confirmed what the "plumber" told me. "The common residential temperature average set point is 120 °F. Tankless hot water heaters are the most efficient when there is no greater than 30 degrees differential required for heating water." Anyway, best of luck with whatever you do.

you can also put a timer on your water heater so it only runs when you need hot water instead of trying to keep water hot all the time