I will ask a stupid question: ARE YOU SURE IT IS THE FIREPLACE
have you plugged something else into the outlet and tested to see that it is still "LIVE" (If it is a duplex outlet.. Plug in at the same time)
Why do I ask this?
On my motor home when I plug in a 1500 watt heater.. Some of the outlets give me "hot wire" aroma.. Not something I care to smell cause it is often followed by one of two things.
1 Circuit failure
2 Visit from Fire Dept.
To solve this I have added a few outlets to this MH.. these are all 15/20 amp outlets (Save one that's 20 only) and all wired with 12GA wire instead of 14, No more hot wire smell, No more problems.