Too cold for water?

[Pogo929]

Newbie here, it’s been below freezing for a couple days, pretty sure the little bit of water left in the water heater is frozen. My question, it’s only going to get to mid 40s the day we leave. If I fill the freshwater tank, do I need to worry about ice in the heater if it doesn’t melt before I hook up water? Should I attach to city water hookup and run water through all the pipes first?
Any advice is appreciated

[MrMark52]

If your water heater is frozen, it’s very likely the rest or parts of the rest of your plumbing system is frozen.

If frozen, it will take longer for your water heater to thaw than the rest of your piping.

If you can get freshwater to start flowing, watch carefully for any ruptures in the piping and fittings. Inspect each and every one with hose pressure applied.

Compromised (by having been frozen) hose to fitting connections don’t usually just drip, but again, inspect carefully so as to minimize/eliminate water damage.

[Bigd9]

Should I attach to city water hookup and run water through all the pipes first?
Any advice is appreciated

That's what I would do. I'm guessing you are referring to a very small amount of water left at the bottom of the tank after you drained it correct? As the water fills the hot water tank, the ice will melt.

[2cyber71]

You better turn on your heat and warm everything up.
Run the water see if it leaks anywhere
You might have broken water lines.
That would be bad.
My old saying The day you have frozen RV water lines is the day you cry

[tmw188]

Originally Posted by Bigd9

That's what I would do. I'm guessing you are referring to a very small amount of water left at the bottom of the tank after you drained it correct? As the water fills the hot water tank, the ice will melt.

X2 on that although I might add to bypass the water htr with your city water valve and flush out any pink stuff throughout the lines first before filling the water htr. If you don’t you may push some pink into the wtr htr.

[Ray,IN]

The small amount of water remaining in the heater is of no consequence when it freezes, just like the small amount of water remaining in the fresh water tank. The large surface area compared to depth allow ice formation to "hump-up" in the middle instead of expanding sideways.
If you fill your fresh water tank and heater tank with water when outside temperature is above freezing, it will thaw the small amount of ice.

[Gary RVRoamer]

Agree totally with Ray - no worries about the residual water in the tank. Whether you have other things frozen is a separate question.

[Jim_HiTek]

Just emerged from a couple weeks of below freezing temps while living in the RV. I had purposely left water in the tank because I was plugged in with the electrical element on. I did drain and blow the lines before I left for 35 days. Many of which were below freezing. I left the heat on at 40*F.

I agree with others that the small amount of water in the bottom of the tank, frozen, won't likely hurt the tank. And I've found from many years of tempting fate during cold snaps, that the piping and fittings of my '02 Winnebago seem to be well made. I know that milky white PEX is made to withstand freezing and my experience seems to support that.

Back to the question at hand. Use the 'tell-tail' of your water pump to alert you to any leaks. Add water to your tank, disconnect shore water if connected, then flip on the pump. After it comes up to pressure, and stops running, and you've run some water from every faucet and shower so there's no air in the system, just listen for a few hours. If the pump repeatedly runs, you have a leak. It should stay at or near pressure for many hours without running (unless you use the water of course). When I go somewhere or go to bed, I always turn it off to be safe, but right now, I'm confident there's no leaks even after two weeks of sub zero temps. I did have a trouble light and a personal heater running in the web bay too but I was without water for much of that time.