How To Keep RV Holding Tanks From Freezing

How To Keep RV Holding Tanks From Freezing

Published Date: September 22, 2020

Last Updated on December 24, 2022 by Camper Front

Camping out in the cold winter comes with its pros and cons, and the cons can actually be quite daunting; hence most RVers prefer to camp during sunny days.

But that shouldn’t deter you from taking your RV out and head out to some “magical” silvery land; it just means you have to learn how to protect your RV from the wrath of the cold.

One of which is knowing how to keep RV holding tanks from freezing; this will save you from a frozen and probably damaged holding tank you might experience otherwise.

How To Keep RV Holding Tanks From Freezing

Most newer RVs come with insulation on their holding tanks,  but even with that, the insulation might not completely protect your tanks from freezing, and you may need to take some extra steps.

Also, the placement of your holding tanks also affects their susceptibility to freezing. Your RV has three holding tanks:

  • Freshwater
  • Grey (sinks + shower)
  • Black (toilet)

they are located in the underbelly of your RV. If your tanks are above the floor level (often the case in Class B motorhomes or conversion vans), they likely will not freeze because the heat from the interior of your RV will keep them thawed.

However, if your tanks are on the outside of your RV (normally the case in Class A’s, Class C’s, Travel Trailers, and Fifth Wheels) or are closer to the ground, they will be more susceptible to freezing.

So, when deciding which of the following options to take, it is important to consider the location of your holding tanks. To prevent your RV holding tank from freezing, here are a couple of things you can do;

Skirting Your RV

Skirting is actually a mainly recommended form of insulation as it effectively prevents the wind from blowing underneath your RV freezing your water tank and sucking the heat out of your home.

You can also go a step further by applying insulating foam boards around the perimeter of your RV, which helps to prevent it from getting extremely cold underneath.

The skirt is used to protect the underbelly of your RV from freezing; skirting is made of different materials, but vinyl skirting is mostly used. Skirting helps to reduce internal heat loss; it also helps during strong winds to reduce the wind rocking.

Insulating your RV with a skirt will help to keep the inside floor warm. For added efficiency, it is recommended to bury the skirting a few inches into the ground as this helps to add stability and reduces airflow.

When installing your skirting, you want to securely attach it to your RV with heavy-duty velcro; this way, it is easy to remove.

But you also have to apply some precautionary measures when making use of skirting, because rodents are likely to be attracted to the warm dark area created by the skirting. To prevent that, you have to make use of rodent control measures.

Running an RV antifreeze

You are going to need up to 2-3 gallons of antifreeze in order to completely protect your entire RV from freezing and up to 10 gallons in the absence of a water heater bypass, so you want to make sure to buy a bypass kit that matches the size of your water heater as it saves you lots of cost on antifreeze.

Once you have gotten your antifreeze and bypass kit, you need to locate your water heater and water pump on the outside of your RV, then plug the drain plug to empty out the hot water tank.

Always make sure to release the pressure ring while draining, also make sure to turn off every electrical component of the water heater before draining; this is because keeping your camper plugged in will cause the electric element to attempt to heat an empty water tank, which could be hazardous.

The next thing you want to do is remove the water anode rod and inspect it for corrosion. This rod keeps your water heater from rusting, so it needs to be checked consistently and replaced when necessary, as this will help to extend the life of your water heater.

Next, locate your hot water heater bypass and open the valve; it should be empty. Close the valve, and the system is now routed to bypass your water heater tank.

For your water filtration system, remove the cover, then remove the filter and replace the cap. Keep a towel handy for discharge, and you may need a tool to help you remove the cover as it may be too tight to remove with just your hands.

To circulate the antifreeze, you need a hose to connect it to the antifreeze inlet. Do not connect it to the city-water connector or blank tank.

Close all faucets and valves then turn on the water pump then slowly open the faucets and valves closest to the pump, this will drain the remaining water from the line, and the antifreeze will begin flowing from the faucets.

Make sure to open the hot and cold valves individually, and once you see the antifreeze close the valve. Continue to repeat this process with every valve and replace the antifreeze supply once it finishes. For your toilets, you need to keep flushing till the antifreeze appears the same as the shower.

Next, locate your city-water connector then use a screwdriver to open the valve on the outside of your RV; keep it open till you are able to see the antifreeze. You also want to drain your black and grey tanks to allow the antifreeze to run into them also.

Heating Systems

How To Prevent RV Holding Tanks From Freezing

You can actually use heating systems to prevent your holding tank from freezing, and one of the heating options is using a holding tank heater blanket.

A holding tank heater blanket is simply a large electric blanket that can be installed on your black or grey water tanks. Depending on which blanket you choose, you can connect it to a 120-volt outlet or run it off the DC current.

You can also invest in closed-cell spray insulation, especially if you are a regular winter camper; this will coat your RV’s entire underbelly with durable and high-R value insulation. This will help to keep your floor warm and reduce the amount of propane you need to maintain a heated temperature inside your home.

Another great way to prevent your RV holding tank from freezing is adding a water tank heater, because when camping during winter, draining your water tank does little or no good.

Use a self-adhesive backing to fix a water heater underneath your water tank then plug it into a power outlet. Heating pads can also come in handy in situations like this because most of them come with an in-built thermostat that gives you control over the temperature levels.

You can turn up the heat at night when it is the coldest, and you can also lower the heat during the day when it starts to get warm.

Heating pads are technically a series of small electrical resistors which can be used to generate a small amount of heat; combining this method with other insulating options is a great way to combat freezing, especially if you are planning to stay at a campsite with weather below -32 degree for a long time.

Applying a heating pad to your holding tanks and water pipes will help to keep them from freezing and also reduce the risk of wind chill, which contributes to the problem.

You can also try using a lamp in your holding tank compartment as this will help to generate a small amount of heat in the enclosed space, which reduces the coldness of the outside tank.

To further prevent your holding tank from freezing, avoid dumping the tanks until they are almost full because empty tanks are more likely to freeze, ensure to plug the water valves, and hoses with ice; this helps to keep the valves closed and ensures the water stays inside.

Finally, there’s only so much you can do to prevent your tanks from freezing, but if at the end of the day you are still ridden with a frozen tank or pipe, you will need to bust out your hairdryer and thaw any frozen areas, but you have to do this carefully as frozen pipes and tanks are brittle and prone to damage.


A frozen holding tank can create a huge mess, which can be quite a hassle to clean up, and it is less hectic to prevent it.

This is why if you plan on camping during the cold, you have to know how to keep RV holding tanks from freezing, and hopefully, this article has given you all the knowledge you need to do that effectively.

Scroll to Top