Thank you for your question concerning electric tankless water heaters. My general answer would be electric tankless whole house water heaters are not an attractive choice in most cases. The major issue with them is they draw so much electricity when running you will need to add a new 100-120 amp service just to run the water heater. They are efficient but like all high efficiency water heaters the energy savings is when they are not in use.
Both gas and electric tankless water heaters use more energy when they are running than standard gas or electric tank water heaters. The savings comes when they are not in use because when they are off, they are off. The electric “Hybrid” water heater combines a standard electric tank with heat pump technology. There is a small heat pump on top the tank that pulls heat from the garage and uses it to heat water. Again, though when put under demand they lose the efficiency.
Based on family size, water heating is 14-18% of your total energy cost. Your water heating cost could be between $30-$50 per month. Using $40 per month as an estimate of water heating costs, let’s say a high efficiency water heater will save 30%, that is $144.00 per year. Consider the difference in cost between a standard tank and the upgrade. It may take as much as 10 years to pay for the upgrade based on your savings. These are all things you will want to consider before making the decision.
Posted in: Conservation Questions