The Worst Winter Problem for RVers
Most RVs can withstand some chilly weather, but once the temperature dips below freezing, you can run into some problems. If your holding tanks, hookups, or pipes end up freezing, this has the potential to cause some serious damage to your RV. This is why everyone needs to know how to thaw a frozen RV tank safely.
Holding tanks are one of the most exposed parts of an RV, and they can take a long time to thaw naturally. If they’re out of commission, you may have a hard time getting running water in your RV, which is a pain in the neck for everyone.
Best Ideas to Thaw a Frozen RV Tank Include:
There are ways to speed up the thawing process and prevent freezes from happening in the first place. We’ll cover some of the best options below.
Hair dryer/heat gun
One of the most effective ways to thaw a frozen RV tank is to apply heat directly to it. A standard hair dryer will get the job done, but heat guns will be quicker. This method works, but you’ll need to be very careful when you do it! Holding tanks are vulnerable to changes in temperature and you could end up melting the outer layer of the tank if you’re not careful.
Lots of holding tanks are made from ABS and polyethylene, and these are the ones you’ll need to be cautious with. For the best results, start at the top of the tank and work your way to the bottom. Keep the hairdryer/heat gun in constant motion so that you’re never applying direct heat to one area for too long.
Eventually, you should be able to open the termination valve. You’ll be able to heat the contents of the tank moving around at this point. This is the sign that the tank has thawed!
Install a 100-watt bulb inside the RV underbelly
If you want to go for a slow and steady thawing method, you can opt for the 100-watt bulb strategy. This bulb can provide a steady amount of heat that will help warm up the holding tank. You won’t have to worry about extreme temperature shifts because a 100-watt bulb can’t produce too much heat on its own.
This method works best if you have holding tanks that are in an enclosed RV underbelly but are not set up with any kind of heater device. If you install a 100-watt bulb in the underbelly, this will help warm up the space in a gradual and gentle way.
You’ll have to be patient if you choose this method, but it involves less risk compared to a hair dryer or heat gun. It’s also faster than just waiting for the tank to thaw naturally.
Wait for the tank to thaw naturally
If you have no other option and would just like to wait it out, you can also just let your tanks thaw on their own. As long as the weather outside is above freezing, your tanks should be able to melt on their own. This could take multiple hours, so it’s not the best course of action for anyone who’s in a hurry.
You can try running the heater in your RV and/or adding some insulated blankets around the tanks to speed up the process. Letting the tanks thaw at their own speed will help prevent any cracks or damage to the exterior that other methods could cause.
How to prevent your tanks from freezing
Learning how to thaw a frozen RV tank is a good thing to do. However, it’s best if you never have to deal with this situation at all! There are ways to protect your holding tanks so they don’t freeze in the first place. Even in frigid weather, you can take steps to keep your tanks unfrozen.
Use RV antifreeze
This is an easy step that will make it harder for the fluid in your holding tanks to freeze. Antifreeze lowers the freezing point of a liquid, meaning that it can withstand icy temperatures better than pure water can. RV antifreeze or windshield washing fluid can both help stabilize the temperature in your holding tanks. Just flush some of these down your toilet if you’re expecting a cold night.
Insulate RV underbelly
One of the best ways to protect your holding tank is to insulate the underbelly of your RV. Some campers already have enclosed underbellies, but a little extra protection never hurts! Wrapping the tanks in blankets, towels, or reflective foil coverings will help keep the heat inside.
Use RV skirting
RV skirting is another good way to keep the cold out. Skirting can provide extra insulation and will prevent snow and wind from chilling your underbelly. There are lots of options you can choose when it comes to selecting a skirting material.
Tarps, vinyl, plywood, foam, or even dirt and straw can be used as skirting! You can also use an inflatable AirSkirt to provide full protection for the underbelly. Something is always better than nothing. Snow is a fairly good insulator, so you can even pile up snow around your RV if you’re desperate.
Use a pipe heating cable or heated tape
Pipe heating cables or heated tape can keep your holding tanks warm overnight. They can also help thaw a frozen RV tank if necessary, but it’s better if they are used before the situation arises. This Heat Cable for Pipe Freeze Protection is a popular option that will protect your holding tanks and the pipes that lead to them.
Some of these products are designed to turn on automatically once the temperature dips to a certain point. You can also buy them in varying lengths so you can select the option that’s best for your RV.
Drip faucets overnight
Moving water is much harder to freeze compared to stagnant water. If you keep your faucets and showerheads dripping overnight, your holding tanks are less likely to freeze.
Of course, this mainly applies to your freshwater tank and won’t help the black or grey tanks as much. Still, any bit helps! You will want to make sure that your freshwater tanks are in good shape because these are the ones you’ll need for cooking and cleaning in the RV.
If you do all (or at least some) of these tips, you will probably never need to thaw a frozen RV tank. In this case, the best solutions are preventative. Even if your tank is frozen solid though, you have plenty of ways to fix the problem.
Make sure you keep track of all your RV maintenance and repairs with an online tool such as RV LIFE Maintenance from RV LIFE. Not only can you keep all of your documents in one place, but you’ll also receive timely reminders when maintenance is due to help you avoid costly repairs and potentially serious accidents.
Related articles:
- 10 Winter Camping Items You Shouldn’t Travel Without
- How To Winterize An RV Without Antifreeze
- RV Tank Heaters: Do You Really Need Them?

I used to take my old class C skiing year ago and had the tanks freeze up on me a few times. I bought the large one piece 12v pads that were supposed to keep them from freezing. Those were about useless. forced air bullet type propane or kerosene heater a few feet away pointing at the exposed tank of a class C works better than anything. Exponentially faster than a blow dryer and not as dangerous as a heat gun which can easily damage the tank.