Good news. Heat Tape Pro and Pipe Freeze Pro are the only heat cables in the world you can see is working. The GlowCap is the LED end cap used to terminate all of our pre-terminated heat cables. If you see the green light glowing at the end of the cable, the cable is working. We also offer a GlowCap End Seal Kit for field assembled cable systems.
Another quite obvious way of determining if your heat cable is working is to feel if it is warm.