What Type of Breaker Do I Need for a Tankless Water Heater?

The type of breaker you need for a tankless water heater depends on various factors, including the specific model, its electrical requirements, and local codes. Understanding these factors is crucial for safe and efficient installation.

Amperage Requirements

Most tankless water heaters require a dedicated circuit with a breaker rated between 30 to 60 amps, depending on the unit's power consumption. Always consult the manufacturer's specifications to determine the exact amperage needed. For instance, a gas-powered water heater often requires a 120-volt 10 amp circuit breaker, but for electric-powered units, a range from a single 30-amp double-pole breaker to up to three 40-amp circuit breakers might be necessary. Each unit size and model has its own requirements.

Type of Breaker

Double-pole breakers are typically used for tankless water heaters because they operate on 240 volts. This ensures that the full power of the unit is utilized effectively. It is important to select the appropriate type of breaker to match the specific needs of your tankless water heater.

Wire Size

Ensuring that the wiring used is appropriate for the amperage of the breaker and the water heater is crucial. For example, 10 AWG wire is commonly used for 30-amp breakers, while 6 AWG wire is used for 50-amp breakers. Always choose wire that can handle the current without overheating or causing safety issues.

Local Electrical Codes and Regulations

Always check local electrical codes and regulations. These codes may have specific requirements for the installation of tankless water heaters. For instance, the incoming water temperature is often around 40°F to 45°F, and a tankless water heater cannot provide 2 GPM at a 90°F rise unless it is a very large capacity unit.

Professional Installation

It is often recommended to have a licensed electrician install the breaker and the water heater. This ensures safety and compliance with local codes. A professional can also help with the installation of a dedicated circuit, which is essential for the proper functioning of the tankless water heater.

For instance, a tankless water heater powered by propane might require a 120-volt 20-amp circuit breaker to power the electronics. The unit can operate safely and effectively in this setup.

Considerations for Gas-Powered Tankless Water Heaters

Gas-powered tankless water heaters typically do not have the same power requirements as electric units. A 120-volt, 10-amp circuit breaker is often sufficient for a gas-powered unit. However, for electric-powered units, a 30-amp, 240-volt double-pole breaker is a common requirement.

Installation Tips

To ensure the best performance and safety, follow these installation tips:

Use a properly sized breaker, such as a Square D QO breaker, suitable for the heater you are installing. Ensure the amperage drawn is appropriate for the size of the heater you install. Typically, 20-30 amps for a 120-volt unit and 20-40 amps for a 240-volt unit. Keep the run of pipe as short as possible to minimize heat loss. Direct the pipeline from the heater to each bathing area, not from one to the next. Consider using a gas or propane heater for water heating, as it can be more efficient and produce less heat loss.

By following these guidelines, you can ensure that your tankless water heater operates safely and efficiently. Remember, a professional installation can help avoid potential hazards and ensure that your system meets all local regulations.