Travel trailer & RV systems
Find the fault in the order a tech checks it.
Numbered tests from the manufacturer service manuals, cheapest cause first, with the reading you should see on the meter before you buy a part.
- 1Voltage at furnace, blower on
≥ 12.0 V - 2Sail switch closes
0 Ω - 3Limit switch closed
continuity - 4Electrode gap
1/8 in
Most furnaces are found by step 3. The board is step 6. Read the guide.
What's going on?
All 30 guides →12 V Electrical
Batteries, converters, chargers, fuses, and the alarms that go off when voltage sags. Most furnace and fridge problems start here.
- How Long Will an RV Battery Last Boondocking? Load Math for 14 Common Draws Calculator Video
- How to Test a Deep-Cycle RV Battery With a $15 Multimeter (and When You Need a Load Test) Calculator Video
- Lead-Acid vs Lithium in a Travel Trailer Calculator Video
- RV Battery Not Charging on Shore Power Diagnose tool Video
- RV Furnace Runs but the Battery Dies by Morning Diagnose tool Calculator Video
- 7-Pin Plug Not Charging the Trailer Battery Diagnose tool Interactive diagram Video
- Why Is My RV Beeping? Every Alarm, What It Means, and How to Silence It Correctly Diagnose tool Video
Propane Appliances
Furnaces, absorption refrigerators, water heaters, and the stove, plus how much gas they actually burn.
- How Long an RV Water Heater Takes to Heat Up Video
- How Much Propane Does an RV Use? BTU Math for the Furnace, Fridge, Water Heater, and Stove Calculator Video
- RV Fridge Not Cooling but Freezer Is Diagnose tool Video
- RV Fridge Not Working on Propane but Fine on Electric Diagnose tool Video
- RV Furnace Blows Cold Air Then Shuts Off Diagnose tool Video
- RV Furnace Won't Ignite Diagnose tool Video
- RV Water Heater Won't Light on Gas Diagnose tool Video
Water and Tanks
Demand pumps, toilets and seals, holding tanks and their sensors, water heaters, and the air conditioner drip that looks like a roof leak.
- Why Your RV Air Conditioner Drips Inside (and How to Fix It Before the Ceiling Stains) Diagnose tool Video
- RV Black Tank Sensors Always Read Full Video
- RV Toilet Not Holding Water in the Bowl Diagnose tool Video
- RV Water Heater Drain and Anode Replacement, Step by Step (Suburban and Atwood) Video
- RV Water Pump Pulsing or Cycling Diagnose tool Video
- RV Water Pump Won't Shut Off Diagnose tool Video
Towing and Weights
Tongue weight, payload, hitches, and the door-sticker math that decides what your truck can really pull.
- First-Trip Checklist for a New Travel Trailer Video
- Travel Trailer Tongue Weight Calculator Video
- Payload, Not Towing Capacity, Is What Limits Your Truck Calculator Video
- Weight-Distribution Hitch Setup Calculator Video
Roof, Seals, and Seasons
Roof sealants, slide seals, leak hunting, winterizing, and the spring checks that keep water out.
- Camper Roof Sealant Video
- Finding a Water Leak in a Camper Video
- How to Dewinterize an RV and Sanitize the Fresh Tank (With the Bleach Ratio) Calculator Video
- How to Winterize a Travel Trailer Calculator Video
- RV Slide-Out Seal Replacement, and Whether You Need a Slide Topper Video
- RV Slide Won't Go In Diagnose tool Video
Calculators
How they work →Tongue weight & payload
Loaded trailer weight in. Tongue target and remaining truck payload out.
Open calculator → Ah/day → daysBattery runtime
Pick your loads, chemistry, and the overnight low. Get days and the solar to break even.
Open calculator → BTU → daysPropane days left
Furnace rating and outside temperature drive it. Add fridge and water heater.
Open calculator → layout → gallonsAntifreeze & bleach
Pink antifreeze for your fixtures, and bleach for the spring tank sanitize.
Open calculator →How a guide is built
Manual first. Meter second. Parts last.
Most RV advice is a forum thread where the fifth reply is right. These guides start from the service manual, name the part numbers, and say plainly where a propane or 120 V job stops being a driveway job.
- Sequence of operationsWhat has to happen, in order, before the appliance works.
- One test per linkThe reading a good part gives, and what a bad reading means.
- A plain stop lineWhere the job goes to a certified technician, and why.
- Dated and correctableEvery page shows its last revision. Corrections that check out get made.