Will RV holding tanks freeze?

In this blog post, we will answer the following question: Will RV holding tanks freeze?

Will RV holding tanks freeze?

Whether your RV holding tanks will freeze or not, greatly depends on their position. It is well-known that holding tanks placed above the floor level will get warmth from the cabin and will likely not freeze. Still, depending on the area you are camping in or where you are storing your RV, it is possible for the holding tanks to freeze. 

Here are three simple tips that every RVer must know and will protect your Rv’s water system from freezing: 

  1. If your RV is in storage, then all holding tanks must be drained, including the pipes, the pumps, and even the air conditioning. Clean the holding tanks with antifreeze. 
  1. If you are using the RV, then whenever you park it, leave it slightly tilted, so that the water from the drains goes towards the waste tank, so that it does not stagnate in the pipes.
  1. Leave the wastewater tank open, and put a bucket underneath, because if left closed, the water in the tank may freeze, which will come out again when the ambient temperature is better.

What to do if the RV holding tanks freezes?

If you’ve stored your 5th wheel or RV outside and the cold has kicked in sooner than expected, your holding tanks may be frozen and you don’t know what level they were when you put your RV away! Were they full or half full or almost empty?

The relief valve (lever) is closed and… is obviously frozen too! “Nice” problem when we have to be on the road in 2 days! Full or almost empty, you need to fix this problem… and fast!

Understandable anguish and desperate situation for many of us!

But, first of all, you will need to find a place to work warm because at -4 F… you risk freezing if you work outside! A garage bay or warehouse will do the trick for a few hours.

Wear safety glasses and gloves to protect your eyes and hands … in case of the unexpected! Remove any debris or dirt that has accumulated on the sides so that the heat can reach directly to the walls of the tank, which will reduce the exposure time to the forced heat. 

Check that the frost, by the expansion effect, has not caused a crack in the walls, that the connector pipe (s) have not suffered any damage and make sure that the safety washer connecting the ABS pipes to the tank is still in good condition. 

If any of these plumbing items are damaged, you will need to replace them before continuing with the thaw procedure as they are usually not repairable.

 To unfreeze your RV holding tanks:

Start in this order: first the black water tank, then the grey water tank and end with the drinking water tank … if there are several frozen tanks.

If you’re careful, you can use a blow dryer or a forced air heat gun to help thaw your tank faster. But make sure you don’t “heat up” in the same place no matter how long the time is: tanks and connector pipes made of ABS and polyethene can melt quite quickly if the heat released is too hot or if you linger too long. at the same place! And don’t allow the dryer to overheat.

Start at the highest level of the tank and “work” your way down through the exposed sides of the tank until you reach the drain valve. Keep the dryer or gun moving at all times and a minimum distance of 6 to 12 inches from the walls of the tank while maintaining a circular “back and forth” motion. Repeat as needed until you can open the drain valve and hear the contents of the tank flow through your sewer hose.

After the contents have been drained, the black water tank is rinsed in and the valve is closed, add one or two “4-litre” containers of antifreeze or antifreeze liquid to the windshield through the toilet bowl. Make sure the antifreeze strength is applicable for the expected temperatures over the next few days! And be sure it’s non-toxic RV antifreeze and/or windshield washer fluid is allowed to be poured into your septic tank. 

The antifreeze will keep you using your toilet, and running water in sinks and showers even if you are travelling in subzero temperatures. This is because it is more difficult, but feasible in most cases, to continue to use your tanks in temperatures below freezing.

If possible, see if you can add insulation around the sides of the tank, by the time you’ve reached warmer temperatures heading south.

Unfortunately, the only other alternative to think about contains the words “wait”, “spring” and “thaw period”.

If your black water tank is “closed” from below and you cannot reach it, you can place a 100 watt light inside the tank through the toilet bowl to help. keep the inside of the tank warm… after having completely evacuated the contents.

Also, consider purchasing an electric heating pad.

How to Install Heating Pads to Your RV’s Tanks

If you want to make sure that the contents of your tanks remain liquid, even in very cold weather, then you should add some heating pads to the set. Small heating pads can be attached to the outside of the tanks and they will provide enough heat to keep your RV’s tanks warm, preventing interior liquids from freezing. This means you will be able to empty your tanks anytime during your trip, even while it’s snowing!

Step 1 – Apply the heating pads

Before connecting the heating pads to an electrical outlet, you must first attach them to the outside of the tank. The most modern RV heating pads come with adhesive tapes. Simply peel off the backing tape from the back of the tape, then squeeze it to the sides of the tank. Hold it firmly for a few seconds, which should secure the pad to the tank.

Step 2 – Heat the cushions

Now that you have attached the cushions to your various RV tanks, all you need to do is plug them into an electrical outlet to allow the tank to be warmed up. Your cushions can be plugged into one of your batteries or connected to an electrical outlet inside one of the RV’s storage boxes.

How to protect your RV in winter

Below we give you several very useful tips for the best conservation of your motorhome during periods of stop and cold.

  1.  To avoid freezing: A big problem that we must always avoid for a good conservation of the motorhome in freezing in:
  • If you have full butane gas bottles you should leave them well protected so that they do not freeze.
  • All circuits that carry water must be drained: tanks, pipes, pumps, air conditioning. Clean water systems with antifreeze and leave taps running to increase effectiveness. Do a chlorine cleaning in the water tank, rinse it well and it will be ready for its next use.
  1. For battery conservation: If you are one of those who make much less use of the motorhome during the winter, you should know that these are discharged around 3% per month. To avoid finding it downloaded when you go to travel you will have to:
  • Recharge the batteries, put them in a warm place and test them from time to time.
  • You must cut the control panel to 12V.
  • If you have solar panels, it may be enough to keep the batteries in your motorhome charged.
  1.  For tire protection: When motorhomes are parked for a long time, they suffer the constant weight of the vehicle itself causing deformation of the tires. To avoid this deformation there are different products and actions that you can use:
  •  You can put tire chocks that are easy to find in stores with automotive accessories.
  • Another way to lighten the load is by placing hydraulic accessories or metal trestles at different anchor points.
  • Leave the tires inflated with the maximum pressure during the winter or in long parking seasons.
  • Also to protect the tires and the steering system is to keep the wheels straight when you park the motorhome.
  • To protect the tires from the sun and rain, you can use a very simple homemade system, which is to cover them with plastic sheets or bags.
  1. Cleaning: it is highly advisable before leaving the motorhome parked for a long period that you carry out an exhaustive general cleaning of both the exterior and the interior. Use detergent products that are not abrasive to the plastics of the vehicle.
  1. To avoid condensation: During winter, due to the change in temperature between night and day, condensation occurs inside and outside the motorhome, so when it is stopped for several months, mould can occur inside due to excess humidity. 

So that this does not happen if the vehicle is indoors, it is advisable to leave one of the skylights with a minimum opening. If, on the other hand, the motorhome is parked outdoors you will have to leave everything well closed and we recommend the use of a dehumidifying product that is responsible for absorbing all the condensation.


If there was no time to avoid RV pipes from freezing, the water would stop coming out of the tap. To recover the supply, it is recommended not to defrost them with hot water because they could burst the pipes. In that case, it is appropriate to apply dry heat to both the pipe and the meter. Applying it with a hairdryer is a good option.

Likewise, if it is not going to be used for a long period of time, it is advisable to close the stopcock and empty the inside of the installation.

If you have any questions, comments or tips on how to travel in an RV during winter, please feel free to share them!

FAQ on Will RV holding tanks freeze?

How to insulate an RV for the winter?

A little extra insulation, such as curtains and rugs, makes it more comfortable in winter. So, take out the thick bedding or invest in an electric blanket, it will help. Park your RV so that the windows face the sun during the day.

How to store an RV?

Here are our tips for winterizing your RV to protect it against bad weather:

  1. Empty the tanks and the water heater. 
  2. Close the water inlet. 
  3. Pump the antifreeze with the water pump. 
  4. Empty the antifreeze. 
  5. Proceed with caulking. 
  6. Remove the batteries and shut off the propane. 
  7. Clean the RV.

How to insulate a trailer floor?

Foam insulation is the most used product for insulating a trailer roof and it is found everywhere on the market.


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