How to Keep RV Pipes and Water Lines from Freezing While Hooked Up

Where the hose's job ends

RV water lines freezing is a different problem from a frozen hose, and it has a different owner. The hose is yours to choose. The lines, tanks and valves were routed by the RV's builder, and only the builder can say which of them sit in heated space.

Keystone's owner's manual is plain about the stakes: “RV components can be damaged from the effects of freezing. Protection of the plumbing system and related components is crucial. Damages due to weather are not covered under warranty at any time.”

Seven steps for a winter hook-up

You need: the RV's owner's manual, the instruction sheet of your heated hose, a GFCI-protected outlet, insulation for the spigot riser. Where the manual of your RV or the sheet of a product says something different from this page, the manual wins.

1. Read the cold-weather section of the RV's manual

   Keystone writes under “Cold Weather Camping” that some units are equipped with additional features for camping in the cold, and that owners may have to take additional actions or “invest in additional enhancements.” It sends them to the dealer for aftermarket equipment and adds: “The cost of these enhancements would not be warrantable.” Other builders have their own wording. Find yours before the first cold night.

2. Decide between city water and the fresh-water tank

   On the city-water connection, the pressurized hose feeds the RV's whole water system and the pump is not needed. The alternative for a short cold spell is the one Keystone describes for sites without a water source: fill the fresh-water tank and use the on-board pump. Then the hose can be drained and stowed.

3. Bring water to the inlet with a heated hose

   If you stay connected, the hose has to be a heated one, set up by its sheet: fully uncoiled, the thermostat in open outside air, plugged directly into a GFCI-protected outlet. PIRIT: “Do not use extension cords.” The hook-up is laid out step by step under how to keep an RV water hose from freezing.

4. Deal with the unheated parts outside

   The spigot, the pressure regulator, the inline filter and the fittings hold water and get no heat from the hose. Insulate the spigot riser if the park allows it; see frozen spigot. An exterior filter is the easiest part to take out of the frost altogether.

5. Check exposed lines before adding heat

   If a line runs exposed under the RV, read what is printed on it. Pipe heat cable is limited by its makers to named rigid materials, and many RV lines are flexible tubing. The next section has the details.

6. Look after the waste side

   A sewer hose that stays connected lies fully outside, and nothing warms it. Standard heat tape must not go on it, because it is a hose. Heated sleeves are sold for the purpose.

7. Winterize when the RV will stand unheated

   Leaving for a week in January is not “hooked up” any more. Keystone describes two methods, compressed air or RV antifreeze for potable systems, and warns: “DO NOT USE Automotive Anti-Freeze.” Many owners have the dealer do it.

Adding heat to the lines themselves

Three product types are sold for this, and each has a narrow place.

Pipe heat cable, 120 volts. Frost King allows its kits on copper, iron or Schedule 40 plastic water pipes only, never inside walls, floors or ceilings, and never on a hose. On an RV that leaves a few spots, such as a rigid, accessible supply pipe of a named material. The Frost King HC6A kit^* (paid link) is the cable whose rules can be read before buying; the HEATIT cable^* (paid link) is described as self-regulating by its seller, and for it we could read no instruction sheet. Both are made for rigid pipes; do not use them on a hose. The page on heat tape for RV pipes compares them and quotes the limits in full.

12-volt pipe heaters. UltraHeat lists adhesive RV pipe heaters at 13.5 VDC, among them one for a 1/2 in supply line with a stated draw of 2.3 amps and others for 1.5 in and 3 in drain pipes. The page we read gives no switch temperatures and no list of pipe materials. These parts are not in our product data; whether your RV's 12-volt system can carry them is a question for the dealer.

A heated sleeve for the sewer hose.

Its −45 °F figure is the maker's claim, and its page states no wattage. The alternatives are on the page about the heated RV sewer hose. How a product is chosen here without trials of our own is described under how we compare.

Typical mistakes

• Buying a heated hose and stopping there. PIRIT: “This hose is NOT designed to provide freeze protection to your water supply.” Whether a heated hose is enough for the pipes is answered under will a heated hose keep RV pipes from freezing.
• Tucking the hose's thermostat into the wet bay. PIRIT requires the thermostat to be exposed to ambient temperature, not in a heated environment or an insulated compartment. In a warm bay it keeps the heater off.
• Leaving the filter and regulator on the spigot. They are the first parts to freeze, and nothing warms them.
• Running heat cable along flexible tubing because a forum said so. The cable's instructions decide, not the forum.
• Trusting a temperature rating to cover the whole hook-up. Camco's page says its hose prevents freezing down to −20 °F. That is the maker's claim for the hose, and it says nothing about the RV.

Models and lengths of heated hoses are compared under heated RV water hoses. The heated water hose overview explains what the product does and where its job ends.