A red LED on the front of the unit means a consumable has run out and needs to be replaced. Replace the consumable which will be the smoke cartridge and / or the smoke generator.
1.
Replace the consumable which will be the smoke cartridge and / or the smoke generator.
2.
Switch the unit on. If a new generator has been installed the unit will automatically run a "purge" cycle.
3.
With the front of the unit facing you, cover the inside right of the cup that joins the yoke (where you can see the clear plastic lens).
This will start a smoke test sequence for 2 minutes or until you remove your hand. Smoke should be produced during this time, but repeat 3-4 times if not successful.