Electrical question regarding extension cords and radiant heaters

[F. Bennett Veteran Find all posts View Profile Close F. Bennett]

Hoping there are some skilled folks here with an electrical background.
My greenhouse will be completed soon, but I have the dilemma of not having a receptacle within 6' of my radiant heater. I understand it is NOT recommended to use an extension cord with a radiant heater (1500 watts). I also understand that it can be done... The shorter the run, the 'safer' it is.
The circuit I want to use is 15amps (14 gauge). According to my electrical panel, this circuit is for my outdoor receptacles and bathroom receptacles. We never use those receptacles. Not even a hair dryer. So I figure if I have to use the 1500 watt setting on the heater, I wouldn't stress the circuit so much.

• Would it be safe to run a 25 foot 12/3 outdoor extension cord to my radiant heater?
• If so, should I add a GFCI receptacle where the heater plugs into? I have a GFCI receptacle in the bathroom already.

If this is truly unsafe, I had planned to add a junction box where the outdoor receptacle is, and run rigid pvc conduit beside the greenhouse. I don't mind doing it, but an extension cord would be VERY convenient, if safe enough.
Thanks!!

[Iowafig Senior Member Find all posts View Profile Close Iowafig]

Your heater will be drawing 12.5 amps... A good quality 12 gauge extension cord is adequate up to 13 amps. You may trip your 15 amp breaker when it turns on depending on the voltage drop over the cord. Now the 14 gauge wire would be my only concern. The best and safest circuit would be all 12 gauge wire and 20 amp service.

[smatthew Senior Member Find all posts View Profile Close smatthew]

a 25ft 12 gauge extension cord would have a 1% drop - or be "burning up" about 15 watts in the cable. Totally doable. If there is already a GFCI in the bathroom you don't want to add another GFCI where the heater plugs in. Back - to - back gfci's is not recommended. If wired properly, the bathroom GFCI will protect all outlets downstream from it.

[F. Bennett Veteran Find all posts View Profile Close F. Bennett]

Thank you, gentlemen. I appreciate the advice and suggestions!

[COGardener Fig Phenom Find all posts View Profile Close COGardener]

You should not have a problem Frank. I have one that's been running in that configuration all winter.

[cis4elk Moderator Find all posts View Profile Close cis4elk]

I would double check and trip the bathroom gfi to see if you lose power to the cord.

[don_sanders Moderator Find all posts View Profile Close don_sanders]

[Taverna78 Vetern Member Fabio Find all posts View Profile Close Taverna78]

😁

[F. Bennett]

so funny.

[F. Bennett Veteran Find all posts View Profile Close F. Bennett]

Thanks a bunch, guys.