What is the minimum size breaker for an electric furnace?

The minimum size breaker for an electric furnace is typically based on the heating requirements and the total amperage draw of the furnace as indicated by its specifications. Electric furnaces are often designed to handle significant electrical loads, and a 30 Amp breaker is commonly used to protect the circuit.

The 30 Amp breaker is appropriate because it provides enough capacity to handle the normal operating current of most residential electric furnaces while ensuring that there is adequate protection against potential overload conditions. Furthermore, the National Electrical Code (NEC) guidelines suggest that the circuit be designed to handle at least 125% of the continuous load, and a 30 Amp breaker usually meets that requirement for typical electric furnaces.

Other choices represent higher capacities that might exceed the recommended requirements for many standard electric furnaces. Using a breaker that is either too small can lead to nuisance tripping, while one that is oversized poses risks by not adequately protecting the circuit and may not comply with local electrical code requirements.