An RV is nothing less than a home on wheels, which means, it has everything you would expect between the 4 walls of your home. To supply you with fresh water for drinking, showering, and other purposes, an RV comes fitted with different water storage tanks.
Needless to say that when the mercury drops below zero, the water that’s left in the holding tanks of your RV would start to freeze. Not only does this renders these tanks useless, but it can also damage the piping and other metal parts underneath the RV.
It is important that you either don’t let this water freeze or unfreeze it if you forgot to empty the tanks before leaving your RV to sit. If you have no idea how to unfreeze a frozen holding tank for RVs, you’re in luck, we have compiled everything to help you with your RV’s holding tanks.
How Many Holding Tanks Does an RV has?
Every RV has 3 types of holding tanks, namely a freshwater tank, a grey water tank, and a black water tank. As the name tells, the freshwater tank contains water that’s safe for human consumption and cooking purposes. The grey water tank receives water that is used for dishwashing and laundry if required.
Lastly, the black water tank gets toilet waste and wastewater from the RV, so you don’t have to worry about dumping the waste.

A Step by Step Guide to Unfreezing a Frozen RV Holding Tank
Grab your gloves, goggles, and other gear, and let’s unfreeze the stale frozen water in your RV’s holding tanks.
Get a blow dryer and provide heat to the tank momentarily. Do not keep the dryer too close to the tank as it could melt the plastic or cause the nearby wiring to catch fire. Keep in 8-12 inches away and provide equal heat to all the areas of the holding tank.
You could speed up the process of melting the frozen water by adding antifreeze to the holding tank, but in a small amount to prevent contamination of the ground. You could also add salt water to the tank that would defreeze it and help you complete your project quicker. If both of these methods don’t help much, bring boiling water with you in a kettle and pour it into the holding tank.
Once the frozen slab of water inside the tank starts melting, you should check the container for progress.

FAQs
Is it advisable to use a detergent solution for flushing the tank?
There’s no harm in flushing the holding tank with detergent, rather it cleans the area better and makes sure there are no remnants or debris left behind.
What should be the sequence of tank cleaning and emptying?
The holding tanks on an RV should be cleaned in the following sequence:
- Black water tank
- Grey water tank
- Fresh water tank
Should I use antifreeze in the holding tank of my RV?
You should not use antifreeze in the holding tank, as it could get mixed with the freshwater which is highly dangerous for human consumption. Moreover, it could also get duped on the ground and it is not safe for the environment.
If the normal unfreezing method doesn’t work, you could add it in a very small quantity to the holding tank.
All the modern RVs have 3 different types of holding tanks, each of which serves a different purpose. If you leave your RV to sit after a trip and don’t flush its tanks, it is highly probable that water will freeze in the winter.
You could unfreeze a frozen holding tank for RV by using a simple home appliance and get it flushed for the next use. It is imperative that you don’t use any hazardous chemicals for speeding up the cleaning and rather use conventional techniques to get rid of the frozen sludge.
Citations
https://www.forestriverforums.com/forums/f217/frozen-water-tank-197733.html
https://www.jaycoowners.com/forums/f10/frozen-black-tank-53823.html
https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/26611943.cfm
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