Refer to the following steps to winterize a toilet.
- Shut off the water to the toilet at the supply stop on the wall.
- Flush the toilet to drain all water out of the tank.
- Using a sponge, rag or shop-vacuum, remove the remaining water from the tank.
- Disconnect the water supply from the bottom side of the toilet. This will allow the water to drain from the valve.
- Pour RV Antifreeze into the overflow tube of the flush valve to make sure all waterways from the tank to drain have antifreeze in them.
Note: Ensure that all waterlines throughout the entire system are drained, too.