Wednesday, September 28, 2022


How to keep your tanks, water lines from freezing


By Russ and Tiña De Maris

With cold weather arriving soon, one RVer asks: “How can I keep my tanks and water lines from freezing up in cold weather?” It’s a good question, and one we learned about early in our RVing days when we woke up one frosty morning to find our water line looked like an icicle.

When it comes to freezing up your RV, the first rule is: Don’t let it happen. Freezing water in a line is expanding water, and it will likely cause damage. Let’s look outside first. When nighttime lows drop below the freeze point, most RVers abandon any idea of hooking up a hose to their “city water” inlet. Fill the rig’s fresh water holding tank and let your RV’s water pump keep water at the ready. Of course, it’s critical that you keep the RV warm — keep the heat on to keep the rig’s water lines from freezing up.

If you’ll be in camp for awhile and have electrical hookups, some RVers have kept their water hose ice-free by carefully applying “heat tape” to the hose. Heat tape is typically sold in hardware stores to be wrapped around pipes at home to keep them from freezing. When using it on a hose, the trick that’s said to work is not to wrap the hose with the heat tape but, rather, run the heat tape parallel with the hose and tape it on. We’ve never tried it, but some say it works. And it may, provided it doesn’t get too, too cold.

Next, there’s the matter of the sewer hose. Again, if you’re in a park with sewer hookups, we typically recommend leaving the black water valve closed and allowing gray water to flow freely into the sewer. Not good advice in cold weather. Keep both valves closed, and dump only when your tanks fill up. If you’re in serious cold country and your tank valves are not in a heated basement compartment you may find them “frozen shut.” We’ve dealt with this by carefully pouring hot water over the valves to unstick them.

What about holding tanks? Again, if your rig is “winter ready” the tanks are probably safely tucked away inside a heated compartment. Only our truck camper has ever had this option, and we’ve always had to deal with exposed tanks. In our experience, if the weather warms up above freezing by day, we’ve always been good. But if you’re dealing with protracted below-freezing days and nights, you’ll need to do more. If you’re stuck in a cold-weather area, skirting around the rig may help keep some of the cold out. Hay bales are easy, but they mold and attract vermin. Using “real” skirting may be your only option.

Even with skirting, if there’s a danger of a holding tank freeze-up, your last viable option is a holding tank heater. Think of it as an electric blanket for your tank. It sticks on the bottom of the tank and uses electricity to warm the tanks above the freeze point. One manufacturer has a “dual power” system that uses shore power when in camp, and 12-volt power when the rig is under way. At about $100 per blanket (meaning two for the typical RV), it’s not an inexpensive solution.

If cold weather is severe, be concerned about keeping your inside pipes warm, too. Typically basement storage compartments are heated with your rig’s LP furnace. If you try to conserve LP by turning it off and heating with a space heater, you’ve blown keeping the storage compartments warm. We’ve found in really cold weather that it’s best to open the cabinet doors to areas where water pipes run to ensure warm air gets to the precious plumbing.

As a general rule, it’s never a great idea to keep your RV in the open winter air for the season. Look into RV self-storage units in your area.



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David McMullin
2 years ago

Good blog, cold weather RV’ing is always a chalange.
I have 12 long-term RV spots in sub-zero weather that all do a great job from my helpful report “Serviving Winter In A RV” it is easally doable by following all the tips and tricks.
Did you know there lots of fulltime RV’S in Alaska?
Safe Travels
David & Kristy’s RV Adventures

John Padgett
2 years ago
Reply to  David McMullin

Can’t imagine doing it myself. Bought my 1st RV 1971 Rectrans Discoverer from TOM’S PLUMBING AND HEATING in Nov 1971 Anchorage Alaska. Drove to Haines Alaska and ferried to Prince Rupert. Drove on to Seattle. Travelled USA till June 73. Sold rig in Baltimore. Took tow car and all belongings on a deadhead cruise to England. Did UK and Western Europe and back to Alaska. 25+yrs. Yuma,az winters now. Absolutely no desire to ever go back. But Alaska was good to me.

5 years ago

Hay is food. Use straw. Attracts fewer vermin and a lot less likely to mold as it has no food value. It is empty stems.

David McMullin
2 years ago
Reply to  MsM

I agree, but still straw is nesting material.
I never recomend using hay or straw around RV’S, but it can be used as ground insulation around water and sewer pipes and conections.
Also it will help to inclose it in plastic sheeting or tarps.
Safe Travels

J Adams
1 year ago
Reply to  MsM

Hay and straw can also be a major fire hazard in the right conditions.

5 years ago

You can use the much cheaper waterbed heating pads on your holding tanks. They are themally controlled to hold at a certain temp. I have used the successfully for years. I typically find them on Amazon and WalMart for under $60. I put mine on a thermostat cube that only turns on when temps get cold enough (Easy Heat EH-38 is what I have) and they cost under $20. I only use one thermostat cube since I put a triple tap heavy duty extention cord on the cube.

2 years ago
Reply to  LMS

Innovative solution to a serious problem!
1. Do you use a high-wattage or a low-wattage heater?
2. Do you place the heater above or below the tank and where do you place the controller?

David McMullin
2 years ago
Reply to  LMS

Good ideal! How do you fasten the pads to the tanks?

5 years ago

We watch the weather closely, and when we see it is going to freeze, we’ll fill the fresh water tank so we don’t have to deal with the heat tape or a freezing hose. When it warms back up, we fill the holding tank again.

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