While most tankless water heaters require expensive permanent installation, the Ecotemp L5 water heater provides hot water anywhere there is a water spigot and a garden hose. The L5 comes with a propane hose and a telephone-style shower nozzle. To set up the L5, you hang it on nail, attach the water hose, and connect the propane hose to a standard portable propane tank. The burner starts automatically when you turn on the water using the control on the shower nozzle.
My wife and I have a tiny cabin on a piece of mountain land that has a water supply, in the form of a frost-free water spigot, but no other utilities. We bought the L5 two years ago when we got tired of heating water for washing and showers in a pan on our Coleman stove. The L5 makes this glorified camping spot feel luxurious. The heater weighs about 12 pounds, making it easy to move back and forth between the spot where we wash dishes and a small enclosure I built for taking showers. When we leave, we disconnect it, drain it, and store it the cabin.
The heater uses two D-cell batteries to run its automatic igniter. In two years of summer-weekend use, we’ve not yet had to replace the batteries. The heater has two controls: a water-flow dial and a gas-flow dial. In practice, you just turn the gas dial to “max” and adjust the temperature by varying the water flow. When adjusted to a decent temperature for a hot shower, the flow is perfectly adequate.
The heater must be used outdoors. Conceivably, you could mount it to the outside of a cabin and pipe the hot water inside. The water outlet accepts the same kind of flexible water supply hose you use to connect a sink’s faucet to your household water supply.
The L5 is not the only on-demand portable water heater. Coleman’s table-top unit uses small, disposable propane canisters, and has a built in pump, allowing it to be used without a pressurized water supply. The pump’s battery must be recharged every 40 gallons. Available accessories for the Coleman include a shower handset and adapters for bulk propane containers and pressurized water supplies. The Coleman unit’s built-in spigot makes washing hands and dishes more convenient than the L5’s shower handset, and it has a special mode for producing 160 (F) degree water for hot drinks. However, it has 20% less heating capacity than the L5 (which is rated at 37,500 BTUs) and costs substantially more, especially with accessories. Another option, the Zodi travel shower, also uses a battery-powered pump, but provides only 10,000 BTUs and lacks the instant-on feature of the L5 and Coleman heaters. Both the Coleman and the Zodi are free-standing, and do not require a place to hang them. The Coleman costs about $185 (plus $30 for the bulk propane adapter, $25 for the water supply adapter, and $15 for the shower handset), the Zodi $130, and the L5 $120.
In the two years we’ve had the L5, we’ve had a couple small problems. We had to replace the short hose that connects the heater to the shower handset. More recently, the handset itself broke when we left it outside on a very cold night and the water in it froze. Occasionally, the burner will go out in a high wind. On the whole, however, the L5 has been very reliable and convenient. Besides luxury camping, I could see the L5 being useful in a potting shed or an outdoor kitchen.