Propane (LP) System
The liquefied propane gas system that powers an RV's refrigerator, water heater, stove, and furnace. Runs from one or two onboard tanks.
Also called: propane, LP gas, LPG, liquefied petroleum gas, RV propane
The propane (LP) system is the liquefied propane gas system that powers an RV’s refrigerator, water heater, stove, and furnace. Propane is the universal RV fuel for these appliances because it works without electricity, store easily under pressure, and is widely available.
What propane runs in an RV
- Refrigerator (the “absorption fridge” — runs on propane or electric, called “two-way”)
- Water heater (most RV water heaters run on propane, electric, or both)
- Stove and oven
- Furnace (forced-air heat blower runs on 12V but heats with propane)
Tank configurations
| Tank type | Capacity | Found in |
|---|---|---|
| Two 20-lb (5-gal) DOT cylinders | 10 gal total | Most travel trailers, some Class C |
| One ASME-mounted tank, 30-50 gal | 30-50 gal | Most Class A, some Class C |
| Two 40-lb cylinders | 20 gal total | Some larger travel trailers |
How long propane lasts
For typical use (refrigerator + occasional hot water + stove + furnace as needed):
- 10 gal of propane: 7-14 days
- 40 gal of propane: 30+ days
In cold weather with constant furnace runtime, propane consumption can triple.
Refilling at the campground
Two refill mechanisms:
- Removable DOT cylinders (travel trailers): unscrew the cylinder, take it to a propane filling station (Tractor Supply, Costco, RV parks), exchange or refill.
- Fixed ASME tanks (motorhomes): drive the RV to a propane-equipped station. Many campgrounds have on-site propane filling for $3-5/gallon.
Safety considerations
- Propane leaks are dangerous. RVs have built-in propane leak detectors near floor level. If the detector beeps, leave the RV and ventilate.
- Driving with propane on or off: laws vary by state and tunnel. Some tunnels (Massachusetts, Maryland) prohibit RVs with propane turned on. Most road rules allow propane during transit.
- Cold weather: propane regulators can freeze at very cold temperatures. RV-specific regulators are designed for outdoor use.
- High elevation: propane appliances can struggle at altitude. Furnace pilot ignition becomes less reliable.
Refilling vs exchanging
For removable cylinders, refilling is much cheaper than exchanging. A 20-lb refill costs $14-20. An exchange tank (Blue Rhino, AmeriGas) costs $25-30 for the same amount. Most propane stations refill — find one before you need it.