Propane torches are most commonly used to weld or solder metal objects together (such as metal pipes). If your current propane torch is not igniting, there is something wrong either with the nozzle or the gas. Exercise caution when troubleshooting the propane torch. It is best to troubleshoot the torch outside, away from anything flammable.
Turn the gas-release valve to the left to lock the opening up. This prevents any propane from escaping.
Clean off the opening on the propane torch with a soft, damp cloth. This removes any residue from the torch, ensuring the propane has a clear air-flow.
Turn the gas release valve to the right. You should hear a slight hissing noise. If you don't, it means the tank is empty and you need to purchase a replacement.
Test out your lighter before holding it up to the propane torch. If the lighter fails to ignite, it is not going to ignite the propane torch.
Hold the lighter up directly in front of the propane torch. If you hold it too far away the propane may not strike the flame, preventing it from lighting.