Is it normal for a 10 year old block heater to trip a GFCI outlet that is on the same ciruct as many others within 6 sec of pluging in when it is -15F.

 

Yes. Find a plug all by itself for it. Don't run an extension cord if possible. If you must, run a heavy and as short as possible one. If it still trips then it is probably shorted and needs replacing.

 

Problem is its an apt complex, so who knows how the wiring is setup. Gonna have to drag a 50' cord around.

 

GFCI's SUCK!! They're pretty much useless for anything bigger than a clock radio.

 

I run a small air compressor, a table saw, Sawzall, Skillsaw, drills, an Electric demo hammer....and a host of other items off GFCI plugs.

If it trips, either the GFCI is bad, or your block heater is shot.

You should be able to plug another similar load into that plug and see if it's still tripping.

If a GFCI is installed wrong, it just won't work, or will trip on every load.

 

I run a 12 amp pump regularlly from a GFCI outside, works fine.

I've had cords that had just a bit of water in them trip GFCIs. I would first try another cord, and if it still trips, then the cord going to the block heater on he truck is probably shot.

 

Had a GFI in my kitchen with nothing pluged in. Wouldn't reset. Finally pushed REAL hard on the reset button and it reset and then stuff replugged and then all worked fine - FWIW

 

You can always lay a droplight under the pan with a 75 watt bulb. It'll keep it from freezing until you get subzero.

 

At time to leave for work the past week or so its been -5 to -20 in around town. Gotta have heat.