I have two roof heaters, each on its own circuit. It's been about a month since I used them, but the last time they were switched on they both worked well.

This morning I switched them both on when it started snowing. One of them stayed on, but the other now immediately tripped the circuit breaker. That's happened intermittently in the past, and was resolved by resetting the circuit breaker. This time resetting the circuit breaker doesn't work. I reset the circuit breaker 5 times, and each time as soon as I turned the roof heater back on it tripped the circuit breaker.

Any idea how I can find out why this is happening, and how to fix it?

  • Standard single pole breaker? GFCI breaker? Or other type?
    – Tyson
    Mar 14, 2017 at 15:45
  • It's a GFCI breaker (At least that's my assumption since it has a TEST button that force trips the breaker).
    – Ike Walker
    Mar 14, 2017 at 15:51
  • 1
    Yeah, usually when a <X> fault detector trips, it's because the load actually does have an <X> fault. It often seems like the detector is the problem because it worked before I put in the fault detector... but actually, it's been faulting all along. Mar 14, 2017 at 17:56
  • In my experience, GFCI breakers do not age well and start to trip on moderate loads after they are several years old. It may still be a problem with the heater but replacing the breaker is a good first step.
    – psusi
    Mar 14, 2017 at 19:53
  • @IkeWalker -- it's likely a GFPE (Ground Fault Protection of Equipment) breaker, which is similar to a GFCI just with a different trip setting (30mA vs the GFCI's 5-6mA) Mar 14, 2017 at 22:37

1 Answer 1


The breaker stays on before you switch it on, so the fault is in the heater.

These things can be damaged in a number of ways - squirrels may snack on them, ice may drag them around and cut them on a gutter, old age and sunshine may damage the insulation. I suspect the only reliable cure will be replacement, but you could (after snowmageddon 2017 is over - or what we used to call a nice normal snowstorm) look for any obvious faults (with the breaker off, please) if you are comfortable getting up to the roof, when you can do so safely.

  • "so the fault is in the heater". Maybe, probably even, but if the switch is indoors and controls an outdoor outlet which the heater is plugged into there is the possibility of a ground fault associated with the outdoor outlet itself, and not the heater.
    – Tyson
    Mar 14, 2017 at 16:14
  • 1
    @Thson True that, that does happen, especially when the junction box is full of water LOL.. Unplug the heater, and you'll find that out right quick. Mar 14, 2017 at 16:25
  • @Harper I've had one that way.
    – Tyson
    Mar 14, 2017 at 19:48
  • Also, if it is an old breaker, it might be weak. That would call for a simple replacement of the offending breaker.
    – SDsolar
    Mar 14, 2017 at 20:13
  • Ayup... sign of a true DIYer, on the ladder with an extension cord out of a window to a hair dryer to melt the ice out of the offending jbox that is full of ice because they didn't think to use a waterproof connector and the soffit has become a flow path for an ice dam. I've seen several modes of failure in my heater cables: Insulation nicks, let water in., Also the termination may leak, or get torn off if you hang something on it, and ice forms on that. Best practice is to loop back the end.
    – DaveM
    Mar 15, 2017 at 16:51

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