Thursday, November 30, 2023


RV not winterized; camping; temp dropped to 25; worried!

Dear Gary,
I am freaking out! The temperature got down to 25 last night and we have water in our water heater and one gallon of water and a chemical in our black tank. We did blow out the water lines. Should I be concerned about the tank and water heater freezing last night? We were not expecting the temperature to drop so fast. We are camping and I am scared I am going to find a busted tank. —Rhonda F.

Dear Rhonda,

Water heater bypass valves

I doubt any damage was done with one night below freezing, but if the temps are due to dip that low again, you’ll probably have to fully winterize the RV, including the water heater. If you have no water in the hot lines, the only way to blow out all the fresh plumbing lines with the water heater filled is to bypass it via the bypass valves.

Perhaps you only need to drain the heater and all will be fine. You can easily drain the water heater by removing the plug and opening the P&T relief valve on the unit. But do verify all plumbing lines are clear of water — both hot and cold.

The holding tank is likely just fine also. Freeze damage occurs when lines freeze and expand the tubing. One gallon of water in a holding tank, even if it ices over, will not expand enough to cause any damage. It may cause the termination valves to stick a little, but nothing should be hurt. But it might be time to decide to move the RV or fully winterize it if the temperatures stay below-freezing for any length of time. No need to freak, however.

gary-736Read more from Gary Bunzer at the See Gary’s videos about RV repair and maintenance.




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Jim (@guest_37072)
4 years ago

On our trip home in late Oct, we ran into a low of about 20 in Western Nebraska. The only trouble was our low point valves developed a leak. They were cheaply made and I was thinking about replacing them at some time anyway. So far, I have yet to notice any other damage.

We are currently on our way Southwest for the winter. I should know more in the next few weeks.

Rvgrandma (@guest_37067)
4 years ago

If the hot water tank is full but not hot, if any damage the first will probably be the drain plug cracking. That happened to us and live FT in it. I had turned the tank off to save propane thinking it would be fine. Nope – woke up with it leaking due to the plug cracked.

Gene Bjerke (@guest_3589)
6 years ago

We winterize by hooking a line from the pump input to bottles of anti-freeze. We leave them hooked up. We use bottled water for drinking, etc., but we flush the head with anti-freeze. We don’t do all that much in very cold weather, but so far all is okay.

Dann G. (@guest_3574)
6 years ago

This is terrific information. After years of RVing, I’m finding it informative to review things here including the replies. Thanks to everyone.

Steven Scheinin (@guest_3568)
6 years ago

We live in our RV full time, and it is not practical to winterize the water. Our rig has the arctic package. It has worked fine so far. Last year no problem with temperatures in Maryland going to 4 degrees. However we are now on the road and got caught in a cold snap in Virginia. Our only problem was the water line to the refrigerator stopped producing. When temps warmed up ok. Don’t know what to do about that.

AC7880 (@guest_3532)
6 years ago

If your hot water heater has a electrical element in it make sure it is OFF before draining the HW tank. Otherwise you will burn up the element.

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