How to Hook Up a Heated Water Hose: Thermostat Position, Order of Parts, First Power-Up

Result, time and what you need

Result: a hose that is laid out straight, tight at both ends, with its thermostat in the open and its plug in a protected outlet. You need: the heated hose and its instruction sheet, a GFCI-protected 120-volt outlet within reach of the hose's own cord, a pressure regulator, and insulation for the spigot.

This guide covers the hook-up of the hose itself. Whether a heated hose is the right method at all, compared with the fresh-water tank or draining the hose each night, is the subject of the guide on how to keep an RV water hose from freezing. This page rests on the two instruction texts we could read, from PIRIT and Miller Manufacturing. Camco's product page notes that instructions are available in English, but the sheet is not online. Where your sheet says something different from this page, the sheet wins.

Three questions to settle before you start

Which end goes to the spigot?

There is no general answer, and the one manual that should give it does not. In the PIRIT manual, step 2 reads: “Screw the female end (near the electrical cord) of the hose onto your faucet.” The thermostat notice of the same manual says the thermostat “is located at the end of the electric cord attached to the male (water-out) end of the hose.” One sentence puts the cord at the faucet, the other at the far end.

On a hose with one female and one male coupling, the female end is the one that fits a spigot's male thread; some hoses come with an adapter that changes this. Threads, adapters and coupling materials are covered under heated hose fittings and adapters, and what Camco's listings say about its adapter under Camco heated hose instructions. What you have to read off your own hose and its sheet is where the cord and the thermostat come out, and whether that end will be near an outlet and in open air.

Where does the thermostat end up?

This is the rule the PIRIT manual prints in capitals: “THERMOSTAT MUST BE EXPOSED TO AMBIENT TEMPERATURE.” It must not be “in a heated environment or in an insulated compartment of any kind.” Miller: “Keep exposed to outside air, shaded from direct sunlight.”

A thermostat inside a heated wet bay or under a faucet cover reads warm air, and the heater can stay off while the hose outside freezes. Why one small sensor decides for the whole hose is explained on the page about how a heated water hose works.

Where do the regulator and the filter go?

We found no statement from a hose maker on the order of parts. A filter maker does give one: Camco's sheet for its inline filter demands a regulator, shows two positions for the filter and says to protect it from freezing. The page on where the pressure regulator and filter go quotes it. What can be said from the other sources:

• Keystone's owner's manual: “Always use a water pressure regulator to control the water pressure entering the trailer.” It also asks for a hose manufactured for potable water use.
• A regulator at the spigot limits the pressure in the hose as well as in the RV. One at the inlet protects only the RV. Hoses state their own limits: the PIRIT manual gives a working pressure of up to 200 psi, Camco's listing a maximum of 100 psi.
• Wherever they sit, regulator and filter are outside the heated length. The PIRIT manual: “This hose is NOT designed to provide freeze protection to your water supply.”

So the order is your choice, and the frost protection for those parts is your job. The page on the frozen spigot covers the faucet end.

Step by step

1. Read the sheet and inspect hose and cord

   Note which end your sheet assigns to the spigot. Then look over the cord, the plug and the hose. PIRIT: “Inspect the cord before using.” Miller's first instruction is to ensure there is no damage.

2. Check the outlet and the cord's reach

   Find a GFCI-protected, grounded 120-volt outlet that the hose's own cord reaches, and press its test button; the Consumer Product Safety Commission advises testing every GFCI at least once a month. PIRIT: “Do not use extension cords.” Miller: “no extension cords.”

3. Unroll the hose completely

   Lay out the whole hose, even if the run is shorter. PIRIT: “To avoid possible overheating, do not leave hose coiled when plugged in.” If the hose is frozen stiff from storage, the manual makes one exception: “First plug in the hose and allow it to warm before uncoiling or bending.” It gives no duration for that.

4. Fit the regulator and filter

   Attach the pressure regulator and, if you use one, the filter, in the order you settled on above.

5. Screw the hose on in the orientation the sheet gives

   PIRIT: “Make sure the washer is in place inside the female coupling.” “DO NOT pull or tug the hose with excessive force as this may damage the fittings and electronic components.” Miller: treat it like a regular garden hose and avoid kinks.

6. Place the thermostat and route the cord

   Leave the thermostat hanging in open, shaded outside air. Route the cord without strain. On a farm, PIRIT adds: “Route the supply cord and locate the hose so as to prevent damage by livestock.” Miller also advises positioning the hose out of direct wind.

7. Turn the water on and check for leaks

   Open the spigot, then open a faucet inside until the air is out. Keystone recommends inspecting the visible water connections for leaks each time the connection is made.

8. Plug directly into the GFCI-protected outlet

   Water first, power second: Miller writes “Do not leave plugged in without water.” PIRIT: “Plug the 3-prong cord into a Ground Fault Circuit Interrupter (GFCI) or a properly-grounded 3-hole outlet that is protected by a GFCI.” And: “Do not immerse the plug.”

9. Insulate the unheated parts

   Cover the spigot, riser, regulator and filter, and leave the thermostat outside the cover. Do not wrap the hose itself unless its maker allows it; Miller says “Do not insulate the hose.”

First power-up: what to expect

• Nothing, if it is mild. PIRIT: the heater “is thermostatically controlled and will not turn on unless the ambient temperature approaches freezing temperatures.” Miller names below 40 °F. A hose that feels cold at 50 °F is doing what its maker describes.
• A light on the plug, on some models. Camco's listing names an LED plug. It shows that power reaches the cord, not that the heater is on.
• Ice from storage. PIRIT: “If water is frozen inside the hose, allow several minutes for the ice to melt after plugging in the hose and before use.”
• A tripped GFCI. Unplug the hose and inspect the cord and plug. If the outlet trips again, do not keep resetting it; the page on a heated hose that is not heating goes through the causes.

We found no hose maker that publishes a way to test the heater in warm weather, so this guide does not make one up.

Taking it down again

Unplug first, then shut off the water, disconnect and drain. PIRIT and Miller both say to store the hose indoors after winter; the page on storing a heated hose has the routine.

If you are still choosing a hose

The page on heated RV water hoses compares the alternatives by length and documentation, and the heated water hose overview explains the product type.