An electric heater uses enough power that it may take its own breaker panel. Models labeled ?whole house? have a power demand of usually 80 or 180-amps, depending on the model. Most breaker panels are rated 200-amps, not leaving much for a tankless heater. The high amperage requires slots for 2 or 3 double-amp breakers, or something similar. For each breaker there needs to be a set of suitable gauge wires (wiring to existing heater is probably not adequate) running to the heater.
After I couldn't find a plumber to do the job for a reasonable price, I decided to do it myself. I checked to make sure I had the reserve capacity for the job, ordered my unit online and headed off to Home Depot to get the materials I needed. With a circuit tester, a good how-to book and a pipe cutter you could do the same.
When having a tankless hot water heater installed you about moving it to a better spot. Tankless heaters can be mounted almost anywhere, but for efficiency should be close to where it is most needed. Piping your new tankless heater is no more difficult than the average water heater; keeping it simple is usually the best answer. Your plumber can advise you on the best location.
Before you start you want to get estimates. An electric tankless heater is a relatively low cost project, with the unit costing about $650 or less, online. Anything copper is expensive, so add another $200 for materials and if your electrical supply is adequate all you have left to work out is labor. Always get estimates in writing with details. If you can find a neighbor or friend to recommend someone, even better. Someone experienced is good but good plumbing and electrical skills are all that is required here.
Electric power is starting to make a strong comeback as a viable energy source. To find out which is the best for you do some checking. First is the efficiency, with natural gas having an 80-85 percent efficiency rating. This means that 15 to 20 percent of the heat goes up the chimney. Figures show electric tankless heaters operating at 90-99 percent. So even if electric power were slightly more expensive, which would be the better deal. Keep in mind that the cost of natural gas has risen dramatically in the past decade.
Buzzwords like global warming and clean fuels are bringing the message that everyone should try to do their part. It seems certain, as fossil fuels become more expensive to take out of the ground, other energy sources will come online. Whether it is wind power or hydrogen-ion generators that power tomorrows water heater, it probably won't be gas that powers our home appliances.