Useful Resources

Pros & Cons About Tankless Water Heaters

Positive points:

1. Endless supply of hot water if sized properly and used properly.
2. Takes up less space.
3. If properly maintained will outlast a conventional unit.
4. Does not have stand-by losses associated with conventional units. A savings of apporximately $120.00 per year.

Negative Points:

1. Tankless units are limited by the flow rate of water through the unit. If you exceed the unit's maximum flow rate, the water will not be inside the tankless unit long enough to be brought up to temperature. For this reason, these units do NOT work with deck mounted tub fillers or showers with multiple spray heads (without staging multiple units which usually becomes prohibitally expensive.) The actual maximum flow rate is lower than specified by the manufacturer because tankless units are typically rated at a 40-degree temperature rise, not a 90-degree rise as in conventional units. In the winter months, our cold water temperature will be around 42 degrees Fahrenheit. Optimum hot outlet temperature is 130, not 82.
2. Units have the same thermal efficiency as conventional water heaters at 82%. While they do not have a pilot light, they require electricity to operate. Instead of giving the $40 per year to the gas company for the pilot light, you give the $40 to the electric company.
3. It will typically take a little longer to get hot water to your fixtures because tankless units have to heat up.
4. Tankless units cannot be used with a hot water return line without the installation of a separate storage tank.
5. Must de-lime the unit every 3 years minimum at a current approximate cost of $340.00
6. Requires a larger gas line to supply the larger burner (the burner is up to 5 times larger than a conventional water heater.)
7. Exhaust cannot be vented to the existing chimney. Exhaust must vent directly through the wall in a high-grade stainless steel material, terminating at least 4' away from any door, window, or gas meter.
8. Units do not operate if you loose power. Unit controls have to be reset once power is restored. Electronics are susceptible to power surges and spikes.
9. Replacement parts are more expensive and will take longer to obtain.