I need to rewrap which pipe? (HVAC related, long)

So, amongst other things I’ve got this three door reach in freezer that’s been giving me problems for a while. Every few weeks the blowers sound like helicopters trying to take off. That usually means the drain is frozen and the accumulating ice has frozen high enough to hit the fan blades. So that means I come in at night, heat up my scunci steamer, shut down the freezer, tear out the bottom, melt the ice as far down in the drain as I can, then go outside and shoot steam back up the pipe, lather rinse repeat, usually takes between 20 and 45 minutes to get it cleared up. Well, the root problem is, I think, that the drain pipe heater is broken. I mean I know it’s broken, I’m just hoping that’s the solution. So I go to Grainger, pick up a new pipe heater thinking it’ll take maybe an hour and half or so to get the new one on. Not so. The freezer is attached (but sepearte) to a cooler. The drain pipe runs between the two. It’s pretty clear the drain heater was wrapped before the two units were married and there doesn’t seem to be any easy way to get in there to remove the old wire and rewrap it with a new wire. Here’s a picture of what I’m talking about.
You can see the blue wire wrapped around the pipe. Now, in the picture it looks pretty straight forward. But you can’t tell the scale of the project. The pipe looks to be a one inch PVC pipe. The area it goes through is probably about 2.5 to 3 inches wide and about three feet to the outside. Much to small to get my arm in there to work with the new wire. If you look at the next picture in that gallery, you can see another view, and the third one shows where the pipe goes to. It’s the white pipe with the flashlight on it in between the two vertical pieces of metal it continues to the left edge of the picture and then turns to go back behind the freezer. That exposed piece of pipe in the third picture looks like the only section that would be remotly easy to wrap, but for some reason it wasn’t wrapped to begin with. That maybe part of the problem. Also, as the pipe travels to the right, just behind that right most piece of metal it makes a 90 and goes under the freezer to the drain, about a foot back. But it’s 100% inaccessible*, so I can’t wrap that part even if I wanted to, even though that’s where the majority of the ice forms. That first foot or so into the drain. I’m hoping that if I can get the rest wrapped enough heat will makes it way into the pipe that it’ll travel up to that last foot and heat it enough to melt any ice.

I’m thinking I might just try and fish the wire through the inside of the drain and when it comes out the other end I’ll have it come back into the builiding and I can wire it in from there. Kinda inside out from the way it is now.

The other option is to tear all the trim off the 5 door cooler to the left and see if that opens up any more room for me to work. I think it will, but I also think it won’t. That is, I think instead of not being able to reach at all down that channel, it might allow me to reach 6 inches or so. That might be all I need to do this, but I’m not sure yet.

*Of course it’s accessible, but it would involve quite a bit more work then I’m prepared for. I’d probably call in the pros for that job.

In the mean time, I’m going to go put it all back together and try to come up with an idea.

Assuming the temperature in the drain rises as it gets further from the inlet, by which I mean, less subject to re-freezing, maybe you could fish a length of constant wattage cable trace down the inlet for a few feet. A cycling timer could be used as a control, though thermostatic device would work too. In either case you DO need a control, and the terminal end would require sealing from liquid-ala submersible pump splices or similar.
No idea what the NEC says about the above.

Well, the temprature rises towards the end during the summer, during the winter it may drop (When the outside temps are below zero).

Why would I need a control, my plan was to have this always be warm, the same why the one I’m replacing is wired?

I made the assumption that you needed greatest freeze protection at the drain inlet, diminishing from there. Perhaps you do need the entire length protected, not just a few feet.
If “my plan was to have this always be warm, the same why the one I’m replacing is wired”, you would want constant wattage heat trace, but BE ADVISED that uncontrolled it is capable of overheating your PVC pipe, or worse. Think fire, toxic fumes, etc.
Self-regulating cable is probably what you have, but I am not familiar with its use INSIDE piping, and have negative views towards its longevity and ability to maintain a given temperature band.

Here’s the one that I picked up

Should do it. Don’t ignore the GFCI recommendation.