Whenever i have seen those electric fireplaces the instructions said that the unit should be hooked up to a dedicated circuit.Not sure but even the tags on the cord may make mention of this also.
I use a tasco meter now also as mentioned by telsa. It will simulate a load showing what voltage is actually available after the load comes on, and shows the voltage drop on the Hot and neutral
They stopped using federal pacific panels in the USA years ago to many house fires.i thought they went out of business. I screwed up on a service call one time you plug something in to the outside recp it would trip the gfi kept thing there something wrong with the ckt. come to find out it was what was being plugged in to the gfi that was bad making it trip christmas lights outside.
