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It happens to everyone at some point in time. Whether it’s freezing pipes, water hoses or even your RV holding tank, you leave something out in below freezing temps and forget about it until the next day when you need to use it. We are going to explore the best way to unfreeze a black holding tank.
The easiest way to unfreeze a black holding tank is to apply heat to melt down the inside contents from solid to liquid. Using a hair dryer or heat gun would be one of the easiest methods as long as you are careful. Most tanks are made from ABS and polyethylene so long lasting heat could melt a holding tank easily, which could mean buying a new tank.
With the heat gun or hair dryer, start at the top of the tank and slowly work your way down all visible sides of the tank, making sure not to apply heat in one location for too long. Keep the hair dryer or heat gun in motion along side the tank at all times, otherwise you increase the risk of damaging your tank. Repeat the motions up and down the tank until you are able to open the valve and you hear its contents draining.
Once you have your tank thawed out and all the contents are drained, you need to clean and flush out your tank. FloJet makes a portable waste pump that does a great job at emptying holding tanks. The FloJet RV Waste Pump Kit is currently on sale from Camping World.
Now to prevent your tank from freezing anymore in the future, try adding 1 gallon of RV antifreeze into your tank. You can buy RV Antifreeze online from CampingWorld.com - http://www.campingworld.com/shopping/item/50-below-rv-antifreeze-gallon/57726. For the black water tank, you’ll need to add the antifreeze through the toilet and down the shower for the gray water tank. You can also experiment with adding windshield washer fluid to the tank through the toilet or shower.
If you want to go above and beyond, you can always insulate your tank. Use some insulating sheathing, and apply that around your tank using glue or adhesive.
Alternative options that have been used by other RVers:
- Placing a 100 watt trouble light inside the compartment to keep it warm
- Purchase an aftermarket holding tank heating pad from Camping World.
What other tips do you have for thawing out a frozen holding tank?