Both the plumber and the electrician (I needed two 240 Volt circuit breakers installed) said it would be easier and cheaper to keep it in the garage, so I went along with that. I was sorry at first because it takes 20-30 seconds for the hot water to get to my bathroom sinks, but by the summer time that won't be a problem. Otherwise the heater works like a charm.
My electric bill for December was $48. That's with both electric heaters, which are used for a only a few minutes at a time when the hot water is turned on. Some of the cost is off-set by the solar panels I had installed last June.
I'm really pleased with this system. The water heaters might need sediment flushed out every few years, but should last forever. I've read reviews of this brand of electric water heaters lasting for 20 years, which is about as long as the company has been making them.
Electric water heaters are popular in Europe, and there's a German brand that is sold here for home use. I bought a brand manufactured in Connecticut, which is smaller and less expensive. The plumber I hired works at the Livermore Labs, and had experience installing these for bathrooms in unattached buildings, but this was the first home unit he installed.
I offered the old 40 gal. gas heater on FreeCycle San Ramon, and someone snapped it up and took it away later that afternoon. That freed up some nice space in the garage too.
I seem to be starting a trend of firsts in San Ramon. I know my rainwater harvesting system is the first of its kind here. Some people may have small water barrels under a downspout, but not the big tanks I have in my back yard. They are half full now, and I've been using the water to do my laundry for a couple of months. I want to keep using the water during the rainy months, so I leave room for the next rain storm. I posted a 6-minute video of my rainwater system under the title Rainwater System in Northern California on Youtube.
There are a lot of very good videos on rainwater harvesting systems on Youtube if any of you wants to know how to add a system to your home. It won't save you money, but it will enable you to hold onto the water that comes off your house. Water is a precious commodity. Don't let it go to waste.
My house water heater is the EX190TC made by Eemax in Connecticut. I wanted to buy from an American company and not one in Europe or Japan. The model I bought cost $500 + tax, but I later found it on another website for $399 with no tax (ouch!). There's also a model with a digital temperature readout on the front that I would have preferred, but I didn't see until after the one I bought was installed. So it's good to search around before ordering.
The plumbing portion cost only about $300, but that's because my plumber was moonlighting from his day job at Livermore Labs. Most plumbers who sell tankless heaters want you to buy the whole package because they can make more money in markups, so again shop around.
The most expensive part was the electrical because of the 240 wiring required. My electrician had to add a special panel for the new heaters, but he also rewired my old panel and added some outlets and other work for under $2K. My house is 40 years old and needed a lot of electrical upgrades, so now I feel safer with all of this done.