Winterize Cabin Water Lines Before a Hard Freeze

Updated November 11, 2026. Black Friday is coming and early holiday shopping is starting, but if your cabin sits empty until spring, the pipes come first.

To winterize cabin water lines, you shut off the water supply, drain the water heater, open every faucet, and drain the system from its lowest point. Then you blow out what’s left with low-pressure air and put RV antifreeze in every trap and toilet so nothing holds standing water.

Plan on an afternoon for a small cabin. The work isn’t hard, but skipping one step is how people end up with a split fitting under the bathroom floor and a flooded crawlspace in March.

What does winterizing cabin water lines involve?

Winterizing means getting every bit of standing water out of the pipes, fixtures, and appliances so there’s nothing left to freeze and expand. Water grows about nine percent in volume when it turns to ice, and that’s enough to split copper, crack PVC fittings, and pop the connections on PEX.

The places that cause trouble are the low spots and the dead ends. Think of the water heater, the toilet tanks, the sink traps, the washing machine, outdoor spigots, filter housings, and any pipe run that dips before it rises again.

When should you winterize a cabin in West Virginia?

Winterize before the first hard freeze, which means a night that drops to roughly 28 degrees or lower for several hours. In this state, that date depends more on elevation than on the calendar.

A cabin up in Canaan Valley or near Snowshoe can see a hard freeze in October, while a place down along the Ohio or the Kanawha might hold off until well into November. Our guide to when first frost usually hits in West Virginia breaks down the timing by region.

If you’re reading this in November and the cabin is still full of water, don’t wait for a better weekend. A single cold snap with the power out is all it takes.

How do you drain cabin water lines, step by step?

Shut off the water first, then work from the top of the system down to the lowest drain. Here’s the order that keeps things simple.

1. Turn off the main water valve. On a well system, also turn off the breaker for the well pump.
2. Turn off the power to an electric water heater, or set a gas heater to pilot or vacation mode. Do this before draining so the elements don’t burn out dry.
3. Open every faucet in the cabin, hot and cold, starting with the highest one. That lets air in so the water can flow out.
4. Hook a garden hose to the water heater drain valve and run it outside or to a floor drain. Open the valve and let the tank empty.
5. Open the main drain valve at the lowest point in the plumbing, usually near where the line enters the cabin.
6. Flush every toilet and hold the handle down until the tank empties. Sponge out the last inch in the tank.
7. Disconnect the washing machine hoses and drain them. Pull the filter cartridges out of any whole-house filter housings and empty the housings.
8. Open outdoor spigots and leave them open. Disconnect and drain garden hoses.

Leave the faucets and drain valves open for the winter. If a little water does freeze in a line, an open valve gives it somewhere to go.

A crawlspace in November is dark and cold, so bring good light. A rechargeable headlamp keeps both hands free for valves and hoses.

Do you need to blow out the lines with compressed air?

Yes, if the cabin will sit unheated through the winter. Gravity draining always leaves water in sags, elbows, and horizontal runs, and those pockets are exactly where pipes split.

Use an air compressor with a blowout adapter that threads onto a hose bib or the water heater inlet. Keep the regulator low, in the 30 to 40 psi range, since you’re pushing water out and not testing the pipes.

Open one faucet at a time, starting with the one closest to the compressor, and let the air run until it sputters out dry. Close it and move to the next, and don’t forget the hot side, the toilets, and the outdoor spigots.

Where does RV antifreeze go?

RV antifreeze goes in every drain trap, every toilet bowl, and anywhere water sits that you can’t drain or blow out. Use the pink propylene glycol type sold for RVs and boats, which is non-toxic and safe for septic systems in these small amounts.

Never use automotive antifreeze in plumbing. It’s ethylene glycol, it’s poisonous, and it’s sweet enough that pets and wildlife will drink it.

• Pour a cup or two into each sink, tub, and shower drain to fill the trap.
• Pour enough into each toilet bowl to replace the water in the trap, and a little in the empty tank.
• Add some to floor drains and the dishwasher sump.
• Check your washing machine manual, since many front loaders call for antifreeze run through the pump.

A filled trap also keeps sewer gas out of the cabin all winter. That’s a nice thing to come back to in April.

What about a well pump or a spring line?

A well system needs its pressure tank drained along with the house lines. Kill the pump breaker, open a faucet, and open the drain at the bottom of the pressure tank or the tank tee until the gauge reads zero.

A shallow-well jet pump sitting in a pump house or crawlspace has drain plugs on the pump body, and those need to come out. A submersible pump down in the well is usually below the frost line, but the line from the pitless adapter to the cabin still needs draining if it runs shallow anywhere.

Gravity-fed spring lines are common up the hollows in this state, and they’re the hardest to protect. If the line runs above ground or close to the surface, disconnect it at the cabin and let it run free, or drain it at its low point if it has one.

Can you leave the heat on instead of draining?

You can, but it’s a gamble in the mountains. Keeping the cabin at 50 to 55 degrees works fine right up until an ice storm drops a tree on the power line and nobody’s there for three days.

If you go this route, add a remote temperature alarm that texts you when the inside temperature drops. Open the cabinet doors under sinks so warm air reaches the pipes, and insulate any lines in the crawlspace with foam sleeves.

Lines that stay in use, like a supply line coming up through a cold crawlspace, can also get UL-listed self-regulating heat cable under the foam. Wrap the cable per the maker’s instructions and plug it into a GFCI outlet.

If you’ll be up at the cabin on weekends and burning wood, the stove helps, but it isn’t a freeze plan on its own. Check how often the chimney needs cleaning before you lean on it, and figure out how much firewood a winter takes so you’re not short in February.

Frequently asked questions

The whole job comes down to one idea: if water can’t sit anywhere, it can’t freeze anywhere. Shut it off, drain it low, blow it out, and fill the traps with the pink stuff.

Tape a note to the main valve listing every drain you opened, so spring startup goes smoothly. Then lock up and enjoy the drive down the mountain, and if you need any cabin gear before the snow, browse the Cozy In WV deals hub.