Every item here prevents one specific, expensive, well-documented failure. None of them look exciting in the box. All of them cost less than what they protect.

• Adjustable water pressure regulator

  $12–45

  Your RV’s plumbing is built for roughly 40–60 psi. Campground mains routinely deliver 80, 100, sometimes more, and there is no way to know before you hook up. A blown fitting behind a wall floods the rig while you’re out hiking — one of the most common RV insurance claims there is. Buy the brass adjustable kind with a gauge so you can actually see the number, not the tiny inline button.

• Potable water hose — plus a second one for rinsing

  $25–45

  A green garden hose isn’t rated for drinking water, leaches into anything left sitting in it, and tastes like a garage. Buy the white or blue potable-rated hose. Then buy a short second hose in a different colour for rinsing the sewer side, store them in separate bins, and never mix them up. Veteran RVers are near-religious about this, and it’s the one superstition worth adopting on day one.

• Surge protector or EMS

  $80–350Match 30A / 50A

  Campground pedestals live outdoors, are decades old, and were wired by whoever was available. Open grounds, reversed polarity and low-voltage brownouts are ordinary, not rare. One bad pedestal can take out your converter, fridge control board and air conditioner in a single afternoon. A basic surge protector blocks spikes. A full EMS also refuses to pass bad voltage through at all, and it’s the one item on this page worth stretching for.

• Electrical adapters — the “dogbones”

  $20–70

  Your rig has one plug; campgrounds have several kinds of outlet. You will eventually pull into a site at dusk where the only thing that fits is the adapter you didn’t bring. Carry 30A↔50A both directions for your rig, plus a 15A household adapter so you can plug in at home to pre-cool the fridge and test the systems before you go.

• Sewer hose kit, clear elbow and gloves

  $45–100

  This is how the tanks get emptied, and the flimsy hose bundled with a used rig is usually already cracked. Get a 15–20 ft hose with cam-lock fittings. The clear elbow is the part people skip and then buy anyway — it lets you see when the water finally runs clean, so you know the black tank is actually empty rather than hopefully empty. Add nitrile gloves and a dedicated bin nobody else touches.

• Leveling blocks or ramps

  $30–80

  Almost no campsite is flat. Past the misery of sleeping on a slope, an absorption refrigerator — the propane/electric kind in most RVs — can be permanently damaged by running badly out of level, because the coolant stops circulating properly. Interlocking blocks pack smaller; curved drive-on ramps are faster. Either beats a stack of scrap lumber.

• Wheel chocks

  $15–45

  A trailer that rolls while you’re unhitching is a very bad afternoon, and even a motorhome on a slight grade shouldn’t be resting on its transmission alone. Chock before you unhitch, every single time, until it’s as automatic as a seatbelt. Two solid chocks are the minimum; X-style chocks that wedge between tandem axles also cut down the rocking you feel inside when someone walks across the rig.

• High-range tire pressure gauge

  $15–50

  RV and trailer tires run far higher pressure than car tires — often 65 to 110 psi — and the gauge in your glovebox almost certainly tops out below that. Underinflation is the leading cause of RV blowouts, and a trailer tire letting go at speed can tear the fender and sidewall right off the rig. Check every tire cold, before every travel day. Four minutes.

• A second fire extinguisher

  $25–60

  Most RVs ship with one small extinguisher mounted by the door — exactly where you can’t reach it if the fire is between you and the door. Put a second one in the bedroom, and check the gauge on both before you leave. The factory unit in a used rig is very often already discharged or long expired.

• Fresh batteries for the smoke, CO and propane alarms

  $20–90

  An RV is a small sealed box containing propane, a combustion furnace, and an engine or generator. Test all three detectors by pressing the button before you pull out. Note that the propane detector also has an expiry date printed on the face — usually five to seven years — after which the sensor is unreliable and the whole unit needs replacing, not just the battery.

Now the fun part. None of this is urgent — but these are the things people come home from trip one wishing they’d packed.

• Camp chairs and a small outdoor table

  $60–200

  You will spend far more waking time outside the rig than inside it. The interior dinette is not where anybody actually sits. Buy chairs one notch better than the cheapest — they get used every single day and the $25 ones sag by the end of a season.

• Outdoor mat and a doormat

  $35–90

  RV floors are small, and every bit of dirt tracked in stays with you all weekend. A mat under the awning creates a clean zone and a place to leave shoes, which roughly halves the sweeping. Get the breathable mesh kind so it doesn’t kill the grass — some parks insist on it.

• Bedding sized for an RV mattress

  $50–150

  An “RV queen” is shorter and often narrower than a household queen, so the sheets from your spare room won’t fit properly. Measure your actual mattress before ordering anything. A topper is the cheapest upgrade to sleep quality you can make — factory RV mattresses are famously thin.

• Non-skid liner, bins and tension bars

  $30–90

  Everything inside an RV is in motion for hours at a time. Without liner and a tension bar or two, you’ll open the first cabinet at the campsite and catch a cascade of cans. Square containers, soft-sided bins, collapsible anything — round things roll and rigid things rattle for three hundred miles.

• A kitchen kit that lives in the rig

  $50–150

  Trying to remember the can opener every trip is how people end up owning four can openers. Stock the RV with its own pans, knives, plates and utensils permanently and packing drops from an evening’s work to loading food and clothes. Nesting and collapsible pieces earn their price back in cabinet space alone.

• Moisture absorbers

  $15–60

  Four people breathing, cooking and showering inside a small insulated box puts a startling amount of water into the air. Condensation on the windows becomes mildew in the cabinets faster than you’d believe, especially in cool weather. Absorbers in the closet and bathroom plus a cracked roof vent handles most of it.

• A small fan and headlamps

  $30–80

  RV air conditioners are loud and don’t push air into bedrooms well; a 12v or USB fan fixes both the stuffiness and the noise. And every hookup, leveling job and midnight walk to the bathhouse happens in the dark — a headlamp keeps both hands free while you’re handling the sewer hose, which you will appreciate more than you expect.

• RV route planner and campground apps

  Free–$60/yr

  Standard car navigation will cheerfully route a 12-foot-tall rig under an 11-foot bridge, or onto a mountain road with no turnaround. RV-specific planners route by your height, weight and length, and campground review apps tell you whether a site is actually level and whether “big rig friendly” is true. Set them up at the kitchen table, not on the shoulder.

• First aid kit, bug spray, sunscreen

  $30–70

  Obvious, and still the most commonly forgotten box on any list. Stock it in the rig permanently so it stops being something you have to remember. Add tweezers, a tick remover, and duplicates of any prescription that would end the trip if it got left on the bathroom counter at home.

Still wondering

Questions new owners ask