Run every appliance yourself before you pay, and run each one in BOTH ways it can run: the fridge on propane and on electric, the furnace and water heater on a full heat cycle, the air conditioner until it actually blows cold. The four big appliances together can hide $2,500 to $6,000 in repairs, so a 30-minute live test is the cheapest insurance you will ever buy on a used RV. A seller who "had it winterized" or "just hasn't hooked it up" is asking you to pay for working appliances on faith. Don't. Make them work in front of you, or treat them as broken.
Appliances are where used-RV sellers cut the most corners, because a dead fridge or furnace looks identical to a working one when it's sitting cold and quiet in the driveway. This guide walks you through testing all four, what the repairs actually cost, the exact questions to ask, and the conditions that should make you walk. When you are done here, paste the listing and get your RV verdict so you know what the unit is really worth before you negotiate.
Before You Test Anything: Get Power, Propane, and Water Ready
You cannot inspect appliances on a dead rig. Two days before the visit, ask the seller to have the RV ready to run:
- Shore power connected (a working 30-amp or 50-amp outlet, or a generator running). Without it you can't test the AC or the electric side of the fridge and water heater.
- A propane tank with gas in it, valve open. Without it you can't test the furnace, the propane side of the fridge, or the gas water heater. Bring a cheap propane gauge if you have one.
- Fresh water in the tank or a city-water hose hookup, so you can run the water heater and check for leaks.
If the seller "can't get to it" or makes excuses, that is itself a data point. Appliances that work are appliances sellers want to show off. Plan to spend 45 to 60 minutes on the appliances alone, and start the slow ones (fridge, water heater) first so they have time to come up to temperature while you check everything else.
Quick tip: start the fridge on propane the moment you arrive. An absorption fridge can take 4 to 6 hours to fully cool, but you will know within 30 to 45 minutes whether it is dropping temperature at all.
The Refrigerator: The Most Expensive Surprise
Most travel trailers and motorhomes use an absorption fridge (Dometic or Norcold) that runs on both propane and 120V electric, with no compressor. They are quiet, they last 10 to 18 years, and when they die they are eye-wateringly expensive: a new cooling unit runs $900 to $1,800 in parts, and a full replacement fridge is commonly $1,500 to $3,500 installed, verify on the specific model. Some newer rigs use a 12V compressor fridge instead, which is more reliable but still $1,000-plus to replace.
Here is the test that catches a dying absorption fridge:
- Run it on propane first. Turn it on, wait 30 to 45 minutes, then put your hand in the freezer. You should feel it getting cold and hear/smell nothing odd. A faint ammonia smell or a yellow stain on the cooling fins behind the fridge means the sealed unit is leaking. That is a dead fridge. Walk or deduct the full replacement cost.
- Switch it to electric and confirm it also cools. Many fridges fail on one mode only, and a seller may have only ever tested the one that works.
- Check the outside vents (the panel on the RV's exterior behind the fridge) for rust, mud-dauber nests, or soot. Soot or scorching around the burner is a propane-side problem.
- Put a fridge thermometer inside if you brought one. A healthy fridge holds the food compartment around 35 to 40°F and the freezer near 0°F once settled.
Seller questions: How old is the fridge? Have you ever had a "no cool" issue or replaced the cooling unit? Does it cool the same on gas and electric? Walk-away or hard-deduct: ammonia smell, won't cool on one or both modes, or visible cooling-fin leak stains.
The Furnace: Cheap Part, Easy to Fake
The furnace is a forced-air propane unit (usually Suburban or Atwood). The good news: it is the cheapest of the four to fix. A new circuit board is $150 to $300, a sail switch or limit switch is $30 to $90, and a whole replacement furnace is $700 to $1,200 installed, verify on the unit. The bad news: a furnace that only blows cold air is easy for a seller to pass off as "working" because the fan still runs.
Test the full cycle:
- Turn the thermostat to heat and set it 10 degrees above room temperature.
- Listen for the sequence: fan starts, then a click and a soft "whoomp" as the burner lights, then genuinely hot air within 30 to 60 seconds.
- Put your hand at the floor registers. Warm-to-hot is good. Room-temperature air after two minutes means the burner is not lighting.
- Walk outside and confirm the furnace exhaust (a small vent low on the sidewall) is blowing warm air, not just the interior fan moving.
- Let it run two full cycles. A furnace that lights then shuts off after a minute usually has a failing sail switch or a blocked exhaust, often a mud-dauber nest in the vent.
Seller questions: Does it light every time on the first try? Any clicking-but-no-flame issues? When was the propane system last leak-checked? Walk-away condition: none on its own, the furnace is rarely a deal-killer, but log it and deduct if it won't light.
The Water Heater: Test Both Gas and Electric
RV water heaters are small (6 or 10 gallons), made by Suburban, Atwood, or increasingly tankless brands like Truma. Older models run propane only; many run propane and electric via a switch. A new tank-style water heater is $350 to $700 in parts and $600 to $1,100 installed, verify on the model. A tankless unit runs more.
Run it like this:
- Confirm the tank is full of water before you fire it (a dry-fired element burns out instantly, a $40 part but a sign of careless ownership).
- Switch it to gas, wait 15 to 20 minutes, then run a hot tap. Hot water means the burner and gas valve are good.
- Switch to electric and repeat after another 20 minutes. Many failures are one mode only.
- Pull the access panel outside and look at the burner area and the anode rod (Suburban tanks have a sacrificial anode; a fully eaten rod means hard-water neglect). Look for rust streaks, water stains, or a crusty drain plug.
- Check for leaks at the tank and the relief valve while it's hot. Any active drip is a sign the tank is corroding through.
Seller questions: Does it heat on both gas and electric? When was the anode rod last changed? Has it ever leaked? Was it properly winterized and drained? Walk-away or hard-deduct: a tank that leaks when hot (replacement, not repair) or a heavily corroded, weeping tank bottom.
The Air Conditioner: Make It Blow Cold, Not Just Spin
The rooftop AC (Dometic, Coleman-Mach, Furrion, Advent) is a sealed unit. When the compressor or sealed system fails, you replace the whole thing: a new 13,500 or 15,000 BTU rooftop unit is $700 to $1,400 in parts and $1,000 to $2,000 installed, verify on the model and roof type. There is almost no economical repair on a dead compressor.
Test it cold, ideally on a warm day:
- Turn it to cool / high fan and let it run 10 to 15 minutes.
- Measure the temperature drop: hold a thermometer at the supply vent and another at the return. A healthy unit gives a 16 to 22°F drop between return air and supply air. Less than 12 to 14°F suggests a tired compressor or low charge (and RV ACs are sealed, so "recharging" usually is not an option).
- Listen for the compressor kicking in (a deeper hum after the fan), not just the fan blowing room-temperature air.
- Check that the fan runs on all speeds and the thermostat actually cycles the compressor on and off.
- Look at the ceiling around the AC shroud for water stains, which point to a failing roof gasket and a slow leak. While you're up there, this is also a roof-leak red flag worth a closer look (see RV roof leak signs).
- On a unit with a heat pump or heat strip, test that mode too.
Seller questions: What's the temperature drop like when it's hot out? Has the AC ever frozen up or tripped the breaker? Any roof leaks around the unit? When was the gasket last resealed? Walk-away or hard-deduct: fan-only with no real cooling, or water stains in the ceiling around the shroud.
Appliance Inspection Cheat Sheet
Bring this with you. Each row is a 5-minute check.
| Appliance | How to test | Healthy sign | Red flag | Typical repair/replace |
|---|---|---|---|---|
| Absorption fridge | Run on propane 30-45 min, then switch to electric | Freezer cold both modes, no smell | Ammonia smell, yellow fin stains, cools on one mode only | $900-$1,800 cooling unit; $1,500-$3,500 full replace |
| Furnace | Set thermostat to heat, +10°F | Burner lights, hot air in under 60 sec, runs full cycles | Fan runs but air stays cold, lights then quits | $30-$300 part; $700-$1,200 full replace |
| Water heater | Fill tank, test gas then electric | Hot water on both modes, no leaks | Leaks when hot, eaten anode, rust streaks | $350-$700 part; $600-$1,100 full replace |
| Rooftop AC | Cool/high 15 min, measure vent drop | 16-22°F drop, compressor cycles | Under 12-14°F drop, fan-only, ceiling water stains | $700-$1,400 unit; $1,000-$2,000 installed |
All figures are typical North American ranges. Verify the exact part numbers and model years on the specific unit, since prices swing with brand, BTU, and 12V vs absorption designs.
How Appliance Condition Should Move Your Offer
One dead appliance is rarely a reason to walk by itself. Two or more, or any sealed-system failure (fridge cooling unit, AC compressor), is a real negotiating lever and sometimes a walk-away. Add up the honest replacement ranges, then subtract from your offer, because you will be the one writing the check. The used RV offer calculator helps you turn these findings into a number, and the broader used RV inspection checklist covers the rest of the rig (roof, slides, tires, brakes) so appliances don't distract you from bigger problems like water damage or soft floors.
Appliance reliability also tracks with how the rig was used and which brand built it. Heavily-used motorhomes like a Class A or Class C cycle their appliances more than a weekend travel trailer, and build quality varies by maker, so it's worth reading up on the brand and its track record before you commit.
What "It Just Needs..." Really Costs
Sellers love the phrase "it just needs a little work." Translate it before you nod along:
- "Just needs a new board" on the furnace: $150 to $300, fine.
- "Fridge just needs to be turned on longer": maybe, or it's a dead cooling unit at $900-plus. Test it.
- "AC just needs a recharge": RV rooftop ACs are sealed and not designed to be recharged. This usually means a new unit, $1,000 to $2,000.
- "Water heater just needs the element swapped": $40 part if true, but a leaking tank is a $600-plus replacement. Look for the leak.
The pattern: cheap-part stories are usually true, sealed-system stories are usually expensive. When the story and the test disagree, trust the test.
Frequently Asked Questions
Can I really test all four appliances during one showing? Yes, in about 45 to 60 minutes if the rig has power, propane, and water ready. Start the fridge and water heater first since they're slow to warm or cool, then do the furnace and AC while they come up to temperature. If the seller can't get the rig ready to run, treat the appliances as unverified and price them as broken.
The seller says everything works but it's winterized and can't be tested. What do I do? Winterizing only affects the water system, so the furnace, fridge, and AC can all still be tested on the spot. The water heater is the one fair exception. Either ask the seller to de-winterize for the showing or budget for a possible water-heater issue and deduct accordingly. "Can't test it" should always lower your offer, never your guard.
Is a propane leak check part of appliance inspection? It should be. Every gas appliance ties into the same propane system, so before you trust any of them, ask when the system was last leak-tested (a shop does this with a manometer for around $50 to $100). Soot, scorching, or a propane smell near any appliance is a stop sign. Pair this with a look at the overall electrical system since 12V control boards run all four appliances.
Should I hire a professional RV inspector for the appliances? For a rig priced over roughly $15,000, a certified NRVIA inspection ($200 to $500) that includes a full appliance and propane check is usually worth it, because one missed fridge or AC pays for the inspection many times over. For cheaper rigs, the tests in this guide plus a careful walk-through will catch the big-dollar failures yourself.
How old is too old for RV appliances? Absorption fridges typically last 10 to 18 years, furnaces and water heaters 12 to 20, and rooftop ACs 10 to 15, all depending on use and care. Age alone isn't a walk-away if everything tests strong, but in a rig over 12 years old, budget for at least one appliance replacement in your first few years of ownership and factor it into the total cost of ownership.
Found a listing you're nervous about? Paste it and get your RV verdict before you put down a dime.