Electric tankless water heaters are becoming more and more popular in North America thanks to their efficiency, low maintenance, reliability and of course, the promise of an unending supply of hot water. If you are considering installing an electric tankless water heater in your new home or replacing an existing conventional storage tank heater, here are a few important things to keep in mind when making your final decision.
Placement & Pipe Runs
Electric tankless water heaters have improved by leaps and bounds over the years, but they still take several seconds to bring a flow of water to the desired temperature, and they still do not heat water quite as fast as their gas-fired counterparts. Because of this, it’s important that the heater be located as close as possible to the kitchen, bathroom or other outlet where the hot water is needed. Consult with licensed plumber to determine the maximum distance that will give you satisfactory performance. If the distance is too great, installing smaller point-of-use heaters at strategic locations in the house may be a good option.
This is the single biggest consideration, especially if you’re replacing an existing water heater in an older home. Electric tankless heaters are much more efficient than their traditional counterparts over time, but they use a considerable amount of energy when running. For example, the smallest model in the Stiebel Eltron Tempra line, the Tempra 15, requires a 60-amp circuit. My 60 year old house has already had an electrical upgrade and sports a 100-amp main breaker. If the Tempra 15 were running at full power and the HVAC switched on, the main breaker would trip, plunging the entire house into darkness. Furthermore, the largest model, the Stiebel Eltron 36, requires three 60 amp circuits.
Now, in practice, an electric heater will draw much less than its circuit requirements would indicate, but it is foolish to try and get by with an underrated circuit. Installing a smaller water heater to reduce the power requirements is also a bad idea. You’ll only end up frustrated with its inability to keep up with the hot water demands of your home. Contact a licensed electrician to find out if your home’s current electrical system can support a suitable electric water heater. Any decent electrician will be able to do this over the phone using the specifications from the water heater you’ve chosen and some details you can gather from your breaker panel.