An RV’s city water inlet takes 3/4" garden hose thread, so a drinking-water hose, or a pressure regulator, connects to it. Some inlets are female and some male, depending on who made them, so check yours before adding an adapter. Put a regulator in the line, set to the pressure your RV’s manual gives. The RV makers in the table below that give a number say 40 to 50 psi.
The thread on the inlet
It’s standard garden hose thread, 3/4-11.5 NH. Camco’s RV parts call it ¾-11½ NH, and Watts’ sheets for its RV regulators write the hose ends as 3/4" NH and as 3/4" GHT. It’s the thread on the ends of every US garden hose (see garden hose fitting size), and it won’t seal on pipe thread of the same 3/4" size (see hose thread vs pipe thread).
Pentair’s Shurflo city water entry has a female swivel inlet, and Camco’s blow-out plugs screw into the city water inlet. Aquor’s RV City Water Inlet has a male 3/4" garden hose thread. Look at the threads on yours. Threads inside, with a rubber washer, make it female. Threads on the outside make it male.
- Female inlet (threads inside): the hose’s male end screws in.
- Male inlet (threads on the outside): it takes a female hose end. The hose’s female end goes on the spigot or the regulator, so screw a female-to-female hose coupling onto the inlet and the hose’s male end into the coupling.
- Female inlet, female hose end: a male-to-male coupling joins them (see connect two garden hoses). Camco’s TastePURE drinking water hose couplings include a male-to-male one.
A few RV water parts have pipe threads. Camco’s brass backflow preventers are 1/2" or 3/4" male x female NPT. To join one to a hose, use a hose-to-pipe adapter: see garden hose to 1/2" pipe.
City water or the fresh water tank
City water runs the RV’s taps on the campground’s own pressure, with no pump. Water from the RV’s fresh water tank is pushed through by the water pump instead.
Makers differ on whether the city water inlet can also fill the tank. Check your RV’s manual, and look on the water panel for a Tank Fill setting.
- Jayco (2021 Jay Flight): the tank can’t be filled through the city water fill. A separate gravity fill fills it. Jayco’s 2027 towables manual adds an exception for utility centers whose valves allow it.
- Grand Design (Momentum, with a Nautilus panel) and Keystone: the tank can be pressure filled through the city water inlet, with the panel’s valves turned to Tank Fill.
- Winnebago (Solis): the tank has its own Tank Fill Inlet on the water center panel, with the levers set to Power Fill Tank.
Pressure regulator
Water pressure changes from one campground to the next, and it can run high, especially in the mountains. A regulator keeps it down to protect the RV’s plumbing. Without one, o-rings can fail. RV makers give different numbers.
| RV maker | What it says |
|---|---|
| Jayco (2021 Jay Flight, 2027 towables) | A 45 lb (315 kPa) rated regulator, customer supplied |
| Grand Design (Momentum, 2024) | A regulator rated for 40 lb, customer supplied |
| Winnebago (Solis) | An in-line regulator, 50 psi max |
| Keystone | Always use one; no number given |
| Airstream | Built-in regulator rated for 50 psi; no outside one needed |
Camco’s and Watts’ regulators come preset. Camco’s basic plastic and brass regulators reduce the pressure to 40-50 psi. Its adjustable brass one is set at 45 psi, and Camco doesn’t recommend settings above 60. Watts’ LFH560 is set at 40 psi and adjusts from 10 to 60 psi.
Where the regulator goes
Makers put it at different ends of the hose. Watts says to put its regulator on the spigot and run the hose from it to the RV, so the hose is protected too. Winnebago says to connect it in-line between the supply hose and the motorhome’s city water input.
Drinking-water hose
Keep one drinking-water hose only for fresh water to the RV, and use a different hose for winterizing.
The US lead-free rule for plumbing doesn’t cover products made only for non-drinking uses such as outdoor watering and irrigation, so look for a hose labeled for drinking water. Camco’s TastePURE drinking water hoses are certified to NSF/ANSI/CAN 61 for drinking water and to NSF/ANSI 372 for lead content.
If your inlet has a check valve
Check valves are one-way valves. Forest River’s manual says in-line check valves keep the fresh water tank and the pump apart from the rest of the system while you’re on city water. Winnebago’s Solis has a backflow valve in the city water connection itself, a small button in its center.
- Winnebago (Solis, when winterizing): press it gently with a fingertip to drain the city water line.
- Grand Design (the Nautilus panel instructions in its Momentum manual): never push the check valve on the City Water connection while the line has pressure in it, or the valve will be damaged for good.
Turn the water off at the spigot and take the hose off before you touch the valve.
Elbows, quick connects and other parts
- 90-degree elbow: one at the inlet, before the hose goes on, takes strain off the threaded connector and the hose. Camco makes 90° and 45° brass hose elbows for RV water hookups.
- Quick hose connect: lets you connect and disconnect the hose without threading it each time. Camco’s brass ones come with an automatic shut-off or as flow-through.
- Quick connect port adapter: some RVs have a fresh water quick connect port. Camco’s 36180 adapter turns one into a male hose thread connection. It won’t work on an air quick connect port.
- Filter washer: a hose washer with a stainless steel screen that sits in the female end of a hose and catches dirt before it gets into the RV. Camco’s are 40 x 40 mesh.
- Cap: the inlet’s cap keeps dust and dirt out between uses. Replacement 3/4" hose caps and plugs are sold if it’s lost.
To reach a spigot that’s too far away, join two drinking-water hoses (see connect two garden hoses).
Hooking up and unhooking
- With the spigot off, fit the regulator, and a water filter if you use one, where your RV’s manual or the regulator’s instructions say.
- Take the cap off the city water inlet and attach the drinking-water hose to it (with a coupling if your inlet needs one). Screw the other end onto the spigot or the regulator.
- Switch the RV’s water pump off, then turn the spigot on and check both ends of the hose for drips.
- To disconnect, turn the spigot off first, then unscrew the hose and put the inlet’s cap back on.
If a connection drips, start with its washer (see garden hose leaking at the spigot).
Unscrew the hose from the inlet whenever the RV is left unattended.
Joining a hose to something else?
Use the adapter finder