While tankless water heaters have been around for many years,
they have only recently become popular with homeowners.
The concept of producing hot water only when there is a demand
for it makes a lot of sense. This approach eliminates the need for a
storage tank and the energy losses associated with maintaining a
reservoir of 140-degree water. However, there is also a downside
to this approach. Without an available reservoir of hot water, you are
restricted to the amount of hot water that can be "instantaneously"
produced by the tankless unit. There is no reservoir to fall back on to
help you meet increased hot water demands.
Standard electric water heaters typically require a 25- to 30-amp circuit
breaker, whereas tankless water heaters require 50- to 60-amp circuit
protection. Because of this large electrical load, a tankless water heater
will require that higher capacity home wiring and a breaker be installed.
In some cases, wiring also must be installed at your expense between
the distribution transformer in the neighborhood and your electric meter.
For additional information on the performance characteristics and costs of
installing a tankless water heater, SRP recommends that you contact a
licensed electrical contractor. For a list of licensed and bonded contractors,
call the Arizona Electric League's Electric Council at (602) 277-3736 or their
Plumbing Council at (602) 285-5563.