Full disclosure - I own a Tankless gas water heater and love it. I had a 50gal tanked gas water heater before. Due to space constraints, it could not be replaced. It was in the doorway of the utility room.

Here is what I learned when looking at Tankless water heaters. Just like when you want to go solar, you have to get more efficient with your appliances. The things I did to change my plumbing fixtures were intrinsic. All these things below were done as part of replacing aging fixtures and were not related to the tankless decision but made the decision and experience with tankless flawless.

1. Replaced all but one bathroom shower valve with a Thermostatic valve. The last one will be replaced this winter.
2. Replace all shower heads with units that used no more than 2.5gal/min
3. Replaced all bathroom and kitchen faucets with units that used less than 2.5gal/min

My dishwashers and washers already heated their own water and all but one of my Washers can use all cold water as input. The dishwasher and washers were energy efficient and used small amounts of water.

There is a large bathtub in the house and the tankless water heater is wonderful for this. We take a bath maybe twice a week. I am getting a separate temperature controller for the tub bathroom so that the filling can happen without interfering with other activities. Currently, showers take priority.

My house hold has 3 adults in it and we always seem to be in the shower at the same time (3 full bathrooms). With the tankless water heater, this is no longer an issue. I like in Maryland where we get really cold in the winter:-). I have a recirculator with my tankless water heater and that is on a timer. It runs for a few hours in the morning and a few hours in the evening. When the recirculator is not running, it takes about 1minute to get hot water to the farthest location in the house. I may add the point of use tankless heater to the bathroom faucets just because it wastes time to wait for hot water. This issue with hot water at the farthest location was always a problem.

I purchased the largest residential tankless water heater which with a 30degree rise, will get you 9.6gpms. This would theoretically allow me to run 3 showers and a faucet at the same time. My unit is programmed to 110F degrees and the showers are set to about 105F degrees. The thermostat for the tankless is in an easy to reach location in the hallway and I can easily increase or decrease the water temperature. I originally started at 140F which is the max temp. I changed it the first day when I could barely wash my hands without burning them. My temperature rise in the summer is about 35F degrees and 50F degrees in the winter.

When I went with tankless, I had heard all the horror stories of cold water sandwiches, huge volume drops due to cold incoming water and flow rate to get started at the sink. I have not experienced any of this. I think the thermostatic valves in the shower contribute to this quite a bit. I am able to get hot water at the sink in under 10 seconds except for the farthest unit. When the recirculator is running, the water is hot within 2 seconds. Just enough time to flush the water from the steel part of the faucet.

Propane would be my choice in your situation. Electric tanked or tankless water heaters would leave you in a lurch when the power went out. Propane tankless water heaters don't perform as efficiently as the natural gas units but that is true of all propane appliances. I have my tankless water heater hooked up to an uninterruptable power supply in the event of a power failure which we have quite often. I also have a small gasoline back up generator and the tankless unit works fine when connected.

I have a Rinnai RUR98i. This unit has a built in recirculator pump. You can also purchase a separate recirculator with the tankless or tanked unit of your choice. I purchased it from build.com and my plumber installed it. I also installed the scale water filter before the unit and this keeps the unit operational without a lot of build up. The unit is just over a year old and I performed a maintenance in the summer. There was very little build up. I am also installing a whole house filter for sediment and chlorine due to some work the water company is doing in my neighborhood for the next year. I have not selected a solution yet for the whole house filter.

Good luck with your decision.

Wow, great question with specific details and answer from homepro. To over simplify; choose tankless propane if you mostly care about unlimited hot water supply and choose a top of the line heat pump water heater if you mostly care about saving money and helping your indoor air quality.

An E TN basement is perfect for a heat pump water heater. Check out Steibel Eltrons biggest model (they are beasts) and expect a fast financial payback if you are comparing against higher end conventional models. You may not be able to shower back to back, but with some better planning, you could probably make it pay off in a big way.

Sounds like recirculation should be explored, but be smart with the installation. Timers (like homepros), activation buttons or motion sensors are mandatory. Electric point of use might also work for that lone fixture.

I recently did a podcast on water heaters. I find that when you have 2 good options and can't decide, going with a hybrid approach will often give you the best of both worlds.

Maybe consider a conventional storage water heater for most of the house and add a smaller tankless unit in the master bath or in areas where unlimited hot water are needed. Check out the link below for a basic lesson on water heaters.

http://www.byhyu.com/home--podcast/hot-water-heaters-101-learn-about-the-pros-and-cons-of-conventional-and-tankless-water-heaters-byhyu-032

I made myself crazy over this. I went with propane tankless. I love it. I like the water hot. Really hot. And when I want a lot of it, I want it up to my neck.

Electricity is expensive in many places including where I live.

We have never had any issue with multiple users either.

This keeps coming up. But honestly I can't imagine a scenario where I would ever want a tank.

Caveat ... don't know much about the hybrids tbh.

Thanks everyone...I know that it's such a widely discussed topic but like I said I'm ending up even more confused. I appreciate all the info, very helpful!