Most tankless hot water heaters are electric. I've never heard of a propane one.
Electric tankless water heaters can be purchased at a local home improvement store. Stores like Lowe's and Home Depot sell this type of water heater at reasonable prices.
Yes, the tankless water heaters do cost more than the normal water heaters because tankless water heaters are designed to supply hot water only when needed unlike normal ones.
Tankless water heaters are available at most hardware/construction retail stores or online stores. Tankless water heater are much more expensive than regular water heaters.
To find reviews for tankless water heaters, one could check out ConsumerReports, as well as sites that sell tankless water heaters such as Home Depot and Amazon.
While tankless water heaters are significantly more efficient than traditional water heaters, it can take up to 22 years to break even on the cost, due to the initial expense of the tankless water heater itself. Unfortunately, by the time the tankless water heater starts to pay for itself, it will likely have exceeded its 20-year lifespan. http://www.consumerreports.org/cro/appliances/heating-cooling-and-air/water-heaters/tankless-water-heaters/overview/tankless-water-heaters-ov.htm
Tankless water heaters have been around about 30 years. I believe they may have first been used on European trains.
Titan tankless water heaters can be purchased online at Tank the Tank, Hot Water, Local, Amazon, eBay, Titan, Titan Water Heaters, and Tankless Water Heaters.
The purpose of tankless water heaters is to provide a continuous flow of warm/hot water to various faucets in the house. It does this by warming the water on demand, and not storing it.
Tankless water heaters can range in price from $200.up to $1200. Depending on if you are looking to purchase a small under sink unit or a bigger gas fired unit. The benefits for purchasing tankless water heaters are the operating costs are cheaper and they have a longer life than the tank type water weaters. Models start at around $300 for small, under-the-sink units, and range in excess of $1000 for high-capacity units. Bosch and Rheem are probably the biggest names in quality tankless heaters. Also, price may depend on your choice of electric, natural gas, or liquid propane models.
Tankless heaters INC.
Tankless water heaters are produced by a wide range of manufacturers. The Rheem tankless water heater has a cost range from the mid fifteen hundreds to over two thousand dollars.