Wood fired hot tub coils get dirty as you use them. They don't need to be cleaned but we've found an easy way to clean them for those of you who like a shiny stainless steel coil.
Hose down your dirty heating coil to remove excess dirt and soot.
Find a powerful oven cleaning spray. Follow the directions on the can and spray the coil. These sprays have harsh chemicals so make sure you are in a well ventilated area and wearing the appropriate PPE.
After waiting for the spray to work (our spray takes 30 minutes) rinse off the spray and the soot with a hose.
That's it! Enjoy your shiny wood fired hot tub heating coil.