Tankless Water Heater

Unfortunately, the 50-gallon water heater started leaking as soon as we turned it on. Fortunately, it was located outside. Unfortunately, the water was draining into the house and could not be turned off at the source (so we had to turn of the main to the house). Fortunately, we got a home warranty. Unfortunately, our warranty company (Allied Home Warranty) is a miserable pain in the butt and works against me instead of with me and also covers only a small portion of the cost to replace the water heater.

So knowing that if I had the warranty company replace the heater for me, I would get a low-end, cheapest possible replacement, I started looking at my other options. Fortunately, the warranty company would still provide the cost savings of that low-end system, no matter what system I chose. Also, if you get Energy Star certified, there are local and Federal rebates to be had (sorry, the State rebates were gone in hours).

First, you have to determine if you have gas or electric. This makes all the difference in the world. We have gas. Since we want to have the most energy efficient appliance possible, I did a little research. For electric, they do make on-demand (aka tankless) water heaters, but they are not nearly as efficient and cost saving as they are for gas. You can get point of use heaters, which heat the water at the distribution point (shower, sink, etc) instead of the main source. I don't know the pros and cons of these. The best choices for electric are solar or hybrid. I found that one company, A. O. Smith water heaters, has some of the nicest models. Hybrid technology is some of the newest stuff for water heaters and looks great if you have electric. Of course, solar is still the best way to go in terms of energy use, but it is pricey. Note: A.O. Smith is a manufacturer and not an installer or retailer so you'll have to find a local company to buy the unit and install it. While you could do it yourself, these things are heavy and there are a lot of codes and ordinances that must be met for a new install. You also have to pull a city permit.

For gas, the logical option (at least the most popular one) is a tankless on-demand system. What they do is super-heat the water as it is needed instead of constantly storing a large quantity of hot water. While it takes more BTU's to heat the water this way, because it only operates when there is a need, you save a load of energy. Tank heaters run 24/7 whether you are home using hot water or not. What they are not are providers for instant hot water - you still have to wait for that cold water stuck in the pipes to come out before you get hot water. What they do provide is an endless supply of hot water that will not run out. While newer to the U.S., these have been in use in Europe for quite some time now, and if you travel to Europe, you'll likely be using one. There are a lot of manufacturers getting into this market now with the growing popularity of these units, so don't settle for the name you've heard thrown around most often or the ones you see in the big box stores. Do the research. Of course, you can just take my recommendation, because I already did the research! DON'T BUY FROM LOWE'S OR HOME DEPOT! While you may be impressed with their price, they are selling you bottom of the line models, and if you read the forums, you'll find more people complaining than you will satisfied customers. Rheem is the most popular. This is what Home Depot sells. It has very mixed reviews and it looks like a middle of the road, ho-hum model with nothing special. The Bosch model that Lowe's sells looks even worse, with not one happy user.

I believe that Navien sells the BEST tankless water heaters. Several reasons: 1) They are condensing models. The high-heat exhaust gets recirculated into the system to pre-heat the water before it is superheated. This results in a 98% heating efficiency compared to regular tankless heaters' 83% efficiency and a tank unit's 60% efficiency. That means, with a tank, you are heating 40% air that is wasted to the outside. 2) Navien utilized dual stainless steel heat exchangers, providing 3.8 to 4.5 times longer life-expectancy and corrosion resistance over the copper heat exchangers used in other brands. Especially good for hard water conditions. 3) While Navien costs more to buy, they have easily installed PVC venting. The high efficiency of Navien's Condensing Tankless results in lower exhaust temperatures, allowing for the use of 3" PVC which provides a significant cost savings over the dual walled metal vent necessary for other tankless units. 4) The burners are eco-designed resulting in less CO2 and NOx emissions and also dissolves NOx in condensed water to neutralized the alkaline sewage otherwise produced. 5) Tankless water heaters occupy 90% less space than a tank-type heater and wall mounts give you floor room (although to meet code, you still have to have an overflow pan beneath the unit) 6) An optional circulation pump and mini-buffer tank. With this option, there is no minimum flow rate required before the unit starts operating. There is no hot/cold/hot stacking, known as the "Cold Water Sandwich" in other tankless models. If you have the plumbing in your house (likely you do not, but it can be installed), this option will let you have a recirculation system where the cold water in the pipes are sent back to the water heater instead of wasted out of the faucet. This provides significant water savings.

Another consideration in buying water heaters is the size. Tank or tankless, you need enough water for your household. These calculations depend on the number of people in a household and the number of points being used at a time. Consumer Reports used to have a fun water heater sizing calculator to help you determine what size was right for your home, but it has been taken down.  The best source for that information now is onEnergy.gov, but it's a much less entertaining method.

What we got: We used Greenwave Plumbing out of Kyle, TX who I found on Craigslist and was also approved by my home warranty company (thank goodness they providedsomething). We got the Navien 210A with circ pump and buffer-tank, 98% thermal efficiency, 10 GPM. Total cost, including unit, permit, installation, accessories to bring it to code, and removal of the old heater: $3,353. Prices vary by installer, so do shop around and get quotes first. This price does not include the rebate we got back from theCity of San Marcos.

Do I like it? Well, it's hard to be in love with a hot water heater, but it provides plenty of hot water whenever we need it, so I'd say it's doin just fine.