All circuit breakers generate a small amount of heat and may be several degrees warmer than surrounding surfaces. But the temperature of a residential circuit breaker in a panel should not exceed about 140º F; or, on hot days, it’s better to only call it out when the temperature difference between the breaker and surrounding surface exceeds 50º F. The surface temperature should not be established using adjacent AFCI or CAFCI breakers, which run about 20º F hotter than regular breakers due to the heat generated by the AFCI device—even when there is no load on the circuit. The yellow breakers are AFCI in the infrared photo below.

    Using an infrared thermometer is a standard way to check temperatures and, of course, an infrared camera is even better. But putting your finger on the flat plastic surface of any breaker is also a simple way to test: if it’s too hot to keep it there, then you have an overheated breaker.

    For a rundown of the potential causes of overheated breakers, see our blog post What causes a hot circuit breaker in an electrical panel?

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Here’s links to a collection of our other blog posts about ELECTRIC PANELS:

• What causes copper wires to turn green or black in an electric panel?  

• What is the maximum number of circuit breakers allowed in an electric panel?

• When should a corroded or damaged electric panel cabinet or disconnect box be replaced? 

• What is a tandem circuit breaker? 

• My circuit breaker won't reset. What's wrong?  

• What is the maximum gap allowed between the front of a recessed electric panel box and the wall surface surrounding it? 

• What are the requirements for NM-cables entering an electric panel box?

• Why is a fuse box/panel an insurance problem for homebuyers? 

• Why is bundled wiring in an electric panel a defect?

• What is the difference between GFCI and AFCI circuit breakers? 

• Why are old electrical components not always "grandfathered" as acceptable by home inspectors?

• What happens when you press the "TEST" button on a circuit breaker in an electric panel?

• What is a Dual Function Circuit Interrupter (DFCI)? 

• What is the difference between a Combination Arc Fault Circuit Interrupter (CAFCI) and an Arc Fault Circuit Interrupter (AFCI) circuit breaker?  

• What is the difference between "grounded" and "grounding" electrical conductors? 

• What does it mean when a wire is "overstripped" at a circuit breaker?

• Why is an old fuse panel dangerous?  

• Who is the manufacturer of those "bad" electric panels?

• Why is the circuit breaker stuck in the middle? 

• What is a double tap at a circuit breaker?

• What is the right electric wire size for a circuit breaker in an electric panel?

• What is the life expectancy of a circuit breaker? 

• What is the main bonding jumper and where do it find it in an electric panel? 

   Visit our ELECTRIC PANELS page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.