New water heater heats for 1/10th of the cost.
 

I think the title says it all but here are the details.
about two months ago I installed an A.O Smith Vertex water heater, their 70,000 BTU 90% efficient, 50 gallon tank type, forced vent, natural gas water heater, I installed it mid month so my first bill was not something I felt like I should pay attention to, but today we had another utility bill show up, we've had this water heater installed for about a month and a half and this bill shows we used 4 therms of natural gas costing about 11 cents per day or about $3 for the last 28 days that we were billed for.
Compare that to our electric water heater that we removed that was about 10 years old, I figure it was costing $20 to $25 per month to heat with it.
Total installed cost was around $1,500 but our old water heater was going to need to be replaced anyway so we figured why not replace it before it starts leaking and causes damage and causes us to replace it on short notice with something that is not as good as we have now.
So if you look at it from the point of view of replacing a new electric that for whatever reason no longer has any value, with this new natural gas unit, pay back would be about 7 years, until I saw the notice that came with the bill that talked about rate increase, bringing the pay back closer to 5 years assuming there are no more rate increases and that our old water heater would have lasted that long as well.

I was looking for more information on the water heater you posted and found this video describing how the unit works and it's benefits.


http://www.youtube.com/watch?v=U7h-LerlC78

As an alternative you can use an instant on gas heater. We heat with wood but have the LP heater for convience of getting hot water when we want it. It's powered by a 20# LP tank. We go through a tank about every 100-120 days. We keep thinking that putting in an LP furnace and getting a 500 gallon tank but until then this works.

Cost is now 128 dollars including shipping on ebay. It is the MAREY brand. Of course installation is easy but not included.

Is that heater easily changed to nat gas? I need to buy a point of use heater for the kitchen here, but since I plan on renting this place out, it has to be maintenance free. No swapping tanks etc.

Tank less water heaters seem ideal for single people or people who don't use hot water every day, or who don't use a whole lot of hot water, from my figures a 20 pound tank of propane has about 4.5 therms... I think, Natural gas costs me about $.42 per therm or $1.90 for the amount of energy in a propane tank.
Thing is that most on demand water heaters are 60-70% efficient altho the Marely is 54% to 87% (wide range!) efficient and the Vertex water heater is 90% efficient.

My guess is that to make a #20 tank of LP last 100-120 days that you are using about 3 to 5 gallons of hot water per day where I am using about 30 gallons of hot water per day with 4 people in my house.

You are getting a great price on natural. I am sure that you can get these units set up for natural gas. I don't have that option and don't use gas for any other use. Still 60 dollars a year for the luxury of having a hot shower is priceless.

One thing to keep in mind is that the water isn't generally blended with cold water. We set it at the temp to the needed temp right at the heater.

The efficiency of the hot water heater has to be titrated on the energy it takes to keep the water warm in the tank.

For rental I would just get a standard tank style heater and let the tenant pay the bill.

I would have as much trouble putting an inefficient water heater in a rental as I would have putting one in my own home.
That is one of the big issues I have with rental houses that I see, the design and repair of them is done so that they are cheap to build but not cheap to live in, if a builder had incentive to make the houses that they build more efficient then everyone would be better off, one way tho is with rental property, if the property owner makes the place as efficient as possible then they can include the utility costs, that money that would have otherwise been wasted on poor design is now in the pocket of the property owner, with the renter happy because they don't get surprised with heating bills, the owner gets paid back for making good choices and less energy is wasted over all.

Varn, am I correct in thinking that you use, on average, about 5 gallons of hot water per day?

I have a rental duplex. I would never put in solar cells and battery pack, never heat it with wood. Just a standard duty furnace and water heater I just want it to work reliably and not get calls. My tenants just want the same. Putting in a 1500 dollar water heater or a 5000 dollar furnace means that they are going to have to pay higher rent. They will move on in a few years. Much less time than the return on the investment.

as far as my own personal hot water usage. No clue.

I ended up putting the Kill-a-watt meter on to see how much power the fan draws, .27kwh for 115 hours, or what should be 1.69kwh for 30 days or about $.20 worth of electricity per month, on top of the $3 per month in natural gas, I think I can live with this.

As for rental properties, people around here at least, are willing to pay more rent if the utilities are included because otherwise you can end up paying $300 in utilities in the dead of winter on top of that months rent, but that doesn't have to be the case.
This

I don't quite fallow your logic, if a tenant moves after a year or two how is that going to shorten the return on your investment on the building?
A friend of mine is in charge of a few low income rentals and they put solar electric and solar hot water on one of them and because they include utilities in the rent they are seeing a positive cash flow, same friend is the one who told me about the Vertex water heater, even their rentals that don't have solar panels are renovated with energy efficiency as the goal and again, renting to low income people, including the utilities in the rent and they are making a profit where low income rentals are often a net loss that are paid for with grants.

Include the heat in the rent, drive by in the winter. You will find windows and doors opened. I don't think that most on this list think like the average renter. I am just wanting something safe and profitable.

If you like you could buy it and upgrade all you want. It might be near you as it is in Wisconsin