Mobile RV LP Gas Appliance Connection and Orifice Service Across Florida

By Jesse Marcer, Founder - Triton RV Repair  |  September 2026

The Two Failure Points at Every RV LP Appliance

Each propane appliance in an RV is connected to the coach LP supply by two components: a flexible stainless-braided hose that accommodates the slight movement between the fixed coach piping and the appliance body, and an orifice inside the appliance that controls the gas volume reaching the burner. Both are wear items, and both fail in characteristic ways that are diagnosable without removing the appliance from the coach.

The flex hose is the connection everyone can see. It runs from the appliance shutoff valve - a manual quarter-turn ball valve that lets each appliance be isolated individually - to the appliance inlet. In Florida coaches, the combination of UV from sunlight entering through windows and compartment doors, heat exposure from the appliance during operation, and the constant humidity that penetrates even closed compartments causes the rubber compound in the flex hose to harden and eventually crack. The failure is typically at the crimp fitting where the hose meets the brass connector - a point of stress concentration where cracks develop first.

The orifice is less visible but more commonly the problem when an appliance fails to light or lights poorly. Florida coaches stored for the summer months with their exterior vents unscreened invite mud daubers, yellow jackets, and palmetto bugs into the appliance vent paths. When the coach is reactivated in the fall, the foreign material in the vent path may prevent combustion air from reaching the burner properly, or the debris may have migrated into the orifice itself during the months of sitting.

Appliance-by-Appliance Failure Patterns in Florida

The water heater and furnace are the most commonly affected appliances for orifice blockage in Florida because they have exterior vents that are directly exposed to the outdoors. Water heater vents face rearward and sit at a height that mud daubers find attractive for nest building. A fully blocked water heater orifice or combustion air vent produces a unit that attempts to light - you hear the ignitor clicking and may get a brief flame - but cannot sustain combustion because the air-to-fuel ratio is immediately wrong.

The range and oven are more commonly affected by flex hose degradation because they see the highest thermal cycling of any LP appliance in the coach. The range burners go from ambient to several hundred degrees each time they are used, and the flex hose below the range is subject to radiant heat that none of the other appliance connections experience. A range flex hose that has not been replaced in 10 years in a Florida coach is a candidate for preventive replacement regardless of whether it is currently leaking.

The LP refrigerator has the least-used LP circuit of any appliance in coaches that run shore power most of the time. When the refrigerator switches to LP mode - during travel or when shore power is unavailable - an orifice that has been sitting unused with condensed moisture inside can present a startup problem. We clean the refrigerator burner orifice during full appliance service calls as a matter of course because it is inexpensive insurance against a failed refrigerator on a long driving day.

Orifice Cleaning vs Replacement

Most orifice blockages in Florida coaches are spider webs, mud dauber material, or dust accumulation - all of which clean out with compressed air and a fine wire. The orifice itself is not damaged. We never drill an orifice to clear it because the calibrated opening is the entire specification - an oversized orifice delivers too much fuel and produces an uncontrolled flame. The proper tools are compressed air, a fine cleaning wire in the correct gauge for the orifice diameter, and in some cases an ultrasonic cleaner for orifices with hardened mineral deposits.

Orifice replacement is indicated when the orifice itself is physically damaged - corroded, distorted, or has been improperly cleaned with a tool that enlarged the opening. We carry a stock of common orifice sizes for Suburban, Atwood, and Dometic appliances and can replace an orifice at the coach for most common appliance models. The replacement takes about 20 minutes per burner including re-test.

Flex Line Replacement and Material Standards

LP flex lines must be rated for LP gas service - the same flexible hose used for natural gas appliances in a house is not interchangeable, and neither is a generic hydraulic hose. We use stainless-braided flex lines with LP-rated internal rubber compounds, sized correctly for the appliance inlet and the available clearance in the appliance compartment. The correct length matters: too short and the hose puts stress on the fittings with every small movement; too long and it can contact the appliance housing or be pinched.

When replacing flex lines, we also inspect the appliance shutoff valve at each connection. These manual ball valves can seize in either position after years without operation - a seized-open valve that cannot be closed means the appliance cannot be isolated for service without shutting off the entire coach LP supply. A seized valve is replaced during the same service call as the flex line, since the connection is already apart.

Pressure Verification at Each Appliance

After any appliance connection service, we verify delivery pressure at each appliance with a manometer tap in the appliance supply line. The target is 11 inches of water column at the appliance inlet. A reading significantly below this indicates a restriction in the flex line, the shutoff valve, or the coach LP supply. A reading above this indicates a regulator issue. Appliance connection service includes this verification, so we leave knowing each appliance has correct supply pressure - not just that the hoses were replaced and the orifices were cleaned.

Full appliance LP service - covering all appliances in the coach in a single visit - is the most comprehensive offering and typically the best value for coaches approaching scheduled service intervals or returning from extended storage. It combines all flex line inspection and replacement as needed, all orifice inspection and cleaning, pressure verification at every appliance, and a full system pressure test. The written report documents what was found at each appliance, what was replaced or cleaned, and the delivery pressure recorded at each point.

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Frequently Asked Questions