Quote Originally Posted by Mitch21 View Post
1) You cannot parallel wire a 4in with an 11in. I'm no electrician, but you won't be able to parallel a strip of 4in with an 11in. They draw different wattage and your temps would most likely not be as accurate as you'd want. (Not to mention, you could be creating a fire hazard).

2) Assuming you don't go over wattage, you can most definitely use extension cords the way you described. There is no hazard here. I'm running extensions the same way right now.
Maybe I'm not interpreting this right, but electrically speaking, there is nothing wrong with running 4in and 11in tape in parallel. The total load seen by the outlet (or thermostat) will be the sum of the heat tape wattage. Obviously you won't get the same temps out of each strip, but this should be safe if wired properly.