Tony Reeves
A couple in Tennessee bought a used Class A motorhome for $68,000 in 2021. They did a walkthrough, kicked the tires, ran the generator for ten minutes, and handed over a cashier’s check. Three weeks later they were parked in a Walmart lot in Georgia with a blown aqua-hot system, delaminating sidewalls, and a slide room that wouldn’t retract. The repair estimate came in at just over $19,000. I’ve heard variations of this story more times than I can count, and the heartbreaking part is that a thorough pre-purchase inspection would have caught every single one of those problems.
Whether you’re buying your first rig or your fifth, or you’re picking up a rental unit after winter storage, knowing what to actually check before you commit, or before you drive away, can save you from a very expensive education.
Start With the Roof: The Most Neglected Surface on Any RV
Everyone looks at the floor plan. Almost nobody gets on the roof.
The roof is where water damage begins, and water damage is the single most destructive force in any recreational vehicle. It works slowly and silently, rotting out substrate, rusting steel, destroying insulation, and creating mold behind walls where you’ll never see it until a repair technician pulls a panel and goes quiet for a moment.
Get up there. Bring knee pads. Walk every inch of it.
On a rubber EPDM roof, look for cracks or bubbling in the membrane, and pay close attention to every seam and every point where something penetrates the roof surface: AC units, vent covers, antennas, skylights. The sealant around those penetrations should be solid, continuous, and not crumbling or pulling away from the surface. If you see chalky, cracked, or missing sealant, assume water has been getting in.
On an aluminum or fiberglass roof, look for depressions, soft spots when you walk, and any separation at the seams. Tap sections with your knuckles. A hollow, drum-like sound in a spot that should be solid often means the underlayment has rotted out.
While you’re up there, look at the AC units. Open the covers and check the evaporator coils for fins that are bent flat or corroded black. Check the gasket where the unit mounts to the roof opening. A leaking AC gasket over five years can destroy a whole section of roof decking.
Come back down and go inside. Find every seam and corner on the interior ceiling and look for water staining, soft drywall, or any slight discoloration. Open every overhead cabinet and press your finger into the ceiling material. It should feel solid, not spongy.
Slide Rooms, Seals, and the Expensive Stuff That Moves
Slides are the number one mechanical failure point I’ve encountered across six years of full-time travel. They work beautifully right up until they don’t, and when they fail at an inconvenient time (which is always), you can find yourself either unable to close for travel or unable to open at your campsite.
Extend every slide, then retract every slide. Do this twice. Watch the motor engage, listen for grinding or hesitation, and check whether the slide travels smoothly and fully seats against the body seals.
Inspect the wiper seals along the top and sides of each slide. These are the rubber gaskets that press against the slide as it opens and closes, keeping rain and road wash outside. Pull the seal gently away from the body and look for tears, brittleness, or sections where it’s lost its shape. A failing slide seal on a rainy night will soak your mattress, your sofa, and eventually your floor.
Once the slides are extended, go outside and look at the underbelly of each slide room. Push up on it. It should not flex more than a few millimeters. Soft or bouncy floors on a slide room are a red flag for water intrusion that’s already compromised the substrate.
Check the slide topper awnings if the rig has them. Look for tears, pooling debris, or torn stitching at the roller ends.
The Underbelly and Frame: What You Can’t See Is What Kills You
Get on the ground. Bring a flashlight and a knee pad or a cheap creeper.
The underbelly of an RV reveals a lot. Look for the belly wrap material, usually a thin black or white plastic membrane that protects the plumbing, insulation, and wiring from road debris. Check for large tears or sections that are sagging down, indicating the insulation above it has absorbed moisture or shifted.
Shine your light across the main frame rails on a motorhome or the frame of a towable. Look for rust. A little surface oxidation is normal. Deep pitting, flaking rust, or any visible cracks in welds are serious structural concerns.
Look at every junction where water or sewer connections come through the floor. Check the area around the gray and black tank connections for staining or dried residue that suggests a chronic leak. Reach up and feel around the tank bodies themselves if you can get close enough. They should feel solid, not soft or wet.
On a diesel pusher or Class C, check for any sign of coolant or oil drips on the ground or on the frame below the engine. One small coolant drip can become a $4,000 head gasket job quickly.
Systems Check: Water, Electric, and Gas
| RV Component | Issue Found | Potential Repair Cost | Inspection Method |
|---|---|---|---|
| Aqua-hot system | System failure | ~$19,000+ | Run system, check for leaks |
| Roof membrane | Cracks, bubbling sealant | Varies | Visual inspection, tap test |
| Slide room mechanism | Won’t retract | Included in $19,000+ | Extend/retract twice, listen for grinding |
| Delaminating sidewalls | Water intrusion damage | Included in $19,000+ | Press ceiling material, check for soft spots |
| AC gasket | Chronic leaks | $500-$2,000 | Check gasket seal, inspect coils |
| Diesel engine | Coolant leak (head gasket) | ~$4,000 | Look for drips below engine |
| Water heater element | Failed element or burner | $200-$500 | Test electric and propane modes |
Run everything. Not just for a minute. Actually use it.
Water System:
Fill the fresh tank or connect to a water source. Turn on every faucet and let it run. Check under every sink for drips. Flush the toilet and check the seal. Run the shower, then get under the rig or inside the cabinet below and look for any wet spots.
Hook up or turn on the water heater. Most rigs have a 6 or 10-gallon tank unit with both an electric element and a propane burner. Test both modes. A water heater that works on one side but not the other often has a failed element or a dirty burner orifice, which is a relatively cheap fix, but it tells you what kind of maintenance history this rig has.
If you’re planning full-time use, a quality inline water filter rated for RV use is non-negotiable. Campground water quality varies wildly and unfiltered water will eventually destroy your appliances from the inside.
Electrical System:
Plug into shore power if possible. Test every single outlet in the rig with a simple outlet tester, available at any hardware store for under $10. Check the breaker panel for any tripped breakers or any breakers that look heat-discolored or corroded.
Test all 12-volt DC items: lights, fans, slides, slideout lighting. A rig with a weak house battery bank will show you immediately once you disconnect shore power and watch how quickly things start failing.
A battery monitor like a Victron BMV-712 will show you exactly what’s happening with your battery bank in real time. If the rig doesn’t have one, install it. Guessing about battery state of charge is how people get stranded.
If the rig has a solar setup, check the panel mounts on the roof for corrosion or loose hardware. Ask for the controller brand and model and look it up. Cheap PWM controllers paired with lithium batteries are a common mismatch on used rigs.
A surge protector at the pedestal is essential every time you plug into campground power. I’ve seen bad campground power damage inverters, charge controllers, and TV sets. The Progressive Industries units are built for real protection, not just marketing copy.
Propane and Appliances:
Open the propane compartment. Look at the regulator and the pig-tail hoses connecting the tanks. Hoses should not show any cracking or bulging. Press a bit of soapy water on every fitting and look for bubbles.
Test the furnace by running it for at least 15 minutes. A furnace that lights but cycles off early often has a dirty flame sensor, a cheap fix, but again, it’s a maintenance indicator.
Test the refrigerator on both propane and electric modes. Give it 30 minutes on each. An absorption fridge that won’t hold temperature or shows yellow/brown staining around the burner assembly often has a failed or failing cooling unit, which can cost $800 to $1,500 to replace.
Test the stove. All burners, the oven if there is one. Look inside the oven for any heavy carbon buildup or damaged seals.
Tires, Brakes, and Anything That Controls Movement
Tires on an RV don’t just wear out from mileage. They age. The rubber compounds degrade from UV exposure and heat cycling whether the rig moves or not. A motorhome sitting in a lot for three years on the same tires is more dangerous than one that drove 30,000 miles on fresh rubber.
Look at the sidewalls of every tire, including the spare. You’re looking for small cracks, not just in the tread but radiating from the sidewall. These are called checking or crazing and they indicate rubber that has lost elasticity. Look at the DOT code on the sidewall. The last four digits indicate the week and year of manufacture. Anything over six years old on a heavily loaded motorhome is a tire I would not trust on a highway.
On a towable, get under and look at the electric brake drums and magnets. Look for scoring on the drum surface or obvious wear on the pads. Ask if the brakes have been adjusted recently.
On a motorhome, if you can safely check the front brake pads through the wheel spokes, do it. Look for any brake fluid drips on the inside of the wheels. Ask to see the maintenance records for brake service.
Bring some leveling blocks and a level to your inspection. Get the rig on as level a surface as possible before checking anything interior, and use the leveling system to see how it works. Leveling system failures are common on used rigs and a stuck leveling jack can leave you listing hard at a campsite with no quick fix.
Step-by-Step: A Practical Pre-Purchase Inspection Sequence
Sources
Follow this order. It’s designed to save time and catch the big problems early before you spend an hour testing the coffee maker.
- Climb the roof first. Check all sealant, membrane condition, and AC mounts. If the roof is bad, you may want to stop here.
- Check all four exterior walls for delamination. Press firmly every two feet along the lower half of the sidewalls. Any soft, bubbling, or crunchy fiberglass sections are delamination.
- Operate every slide twice. Check seals and slide room floor condition.
- Crawl the underbelly. Frame rust, belly wrap tears, tank condition.
- Inspect all tires for age and sidewall condition. Note the DOT date codes.
- Connect to power or run the generator. Test every outlet. Confirm all breakers are set correctly.
- Run water through the entire system. All faucets, toilet, shower. Check under every cabinet.
- Test water heater both modes. Note how long it takes to heat.
- Run all propane appliances. Furnace for 15 minutes minimum. Refrigerator 30 minutes each mode.
- Run the generator under load for 30 minutes. Turn on the AC. If the generator staggers or surges under AC load, it’s a maintenance or mechanical problem.
- Drive it, if it’s a motorhome. Listen for drive train noise, check steering feel, test the brakes in a parking lot at 15 mph.
- Hire a professional inspector if anything in steps 1 to 11 is unclear. A certified NRVIA inspector charges roughly $200 to $400 and can save you tens of thousands.
The rig you buy will be your home, your transportation, and your biggest ongoing expense rolled into one. Rushing a purchase because you’re excited, or because a seller is creating urgency, is exactly how people end up in a Walmart parking lot in Georgia wondering where it all went wrong. Slow down, work through the checklist, and either hire a professional or reschedule if conditions don’t allow a complete inspection. The right rig will still be there when you come back prepared.
Photo: Kampus Production via Pexels
