Before you begin winterizing, clean your grill so it’s spotless. This will prevent corrosion and make sure that is is not a desirable food source for mice or insects looking for a place to ride out the winter.
- Coat your grill grates with a light layer of cooking oil using a spray or a rag, just like you would when normally seasoning them. This will block out moisture that can rust your grates. while they lie dormant. Just be sure to use an oil that won’t go rancid (coconut oil, palm oil, and grape seed oil are all good examples), replace the grates into your grill, and turn all your burners to high for about a minute or so to vaporize excess oil. Too much oil left on the grates can attract insects and wild animals.
- Wrap your burners in plastic wrap or plastic bags to keep spiders and other insects from nesting inside the vents and burner ports.
- Polish the exterior of your grill to give it an added layer of protection.
- If your grill has an electronic ignition system, remove the battery so the contacts don’t corrode during the winter.
- Remove your rotisserie motor from the grill, if present. Even if it’s waterproof, the motor should be stored either in your home or garage, or within your freestanding grill cart.
- Place an appropriately sized cover over your grill, especially if you plan on leaving it outside throughout the winter months.
- Store your grill in a covered or enclosed area, Always store your propane cylinder upright and in a well-ventilated space.
Source: bbq guys