RV Gas Appliance Conversion Service - Mobile LP System Upgrades Florida
Coast to Coast RV Repair provides mobile gas appliance conversion service on-site at your campground or driveway across Florida - certified technicians, same-week scheduling.
Coast to Coast RV Repair provides mobile gas appliance conversion service on-site at your campground or driveway across Florida - certified technicians, same-week scheduling.
Certified technicians. $299 service call. Same-week scheduling. Call (866) 887-1199.
LP vs. Natural Gas Orifice Sizing - Why They Are Not Interchangeable and How to Calculate Correct Size
Propane and natural gas require different orifice sizes because their energy content per cubic foot differs: LP (propane) contains 2,516 BTU per cubic foot at standard conditions; natural gas contains 1,012 BTU per cubic foot. To deliver the same BTU/hr output, a natural gas orifice must flow 2.5x the volume of an LP orifice. Orifice diameter scales as the square root of the area ratio, so the diameter ratio is the square root of 2.5 = 1.58. A 0.082-inch LP orifice corresponds to a 0.130-inch NG orifice (0.082 x 1.58). In practice, NG inlet pressure (typically 7.0 WC) is also lower than LP pressure (11.0 WC), which further reduces flow - so NG orifices are sized even larger than the energy-content ratio alone suggests. The Suburban SW10DE uses a 0.148-inch NG orifice to compensate for both factors. Running an appliance with the wrong orifice does not just reduce efficiency - it changes the air-to-fuel ratio, causing incomplete combustion, CO production, and sooting that can block the flue and create a carbon monoxide hazard.
Air Shutter Adjustment After Orifice Conversion - Measuring Correct Air-to-Fuel Ratio
The air shutter on an RV appliance burner controls primary air entrainment - the combustion air that mixes with gas before it reaches the burner ports. The stoichiometric air-to-fuel ratio for propane combustion is 23.8:1 by volume; for natural gas it is 9.55:1. Natural gas flames require more total air volume to remain blue (complete combustion) because they burn at a lower fuel concentration. After replacing the orifice, the air shutter must be opened further for NG than for LP. The correct shutter position produces a steady blue flame with a clearly defined 0.25-0.5 inch inner cone and no yellow tips or lifting from the burner ports. Jesse Earl uses a Testo 310 combustion analyzer on full appliance conversions - this measures CO, O2, and CO2 in the flue gas and calculates excess air percentage. The target for LP and NG RV appliances is 30-50% excess air, producing 4-6% O2 in the flue gas. A Testo reading of over 8% O2 indicates too much excess air (shutter too open); under 2% O2 indicates too little (shutter too closed).
Also see: RV LP Gas Systems Services
This page covers gas appliance conversion specifically. For the full range of rv lp gas systems services we offer, visit our RV LP Gas Systems service overview.
Case Study: Gas Appliance Conversion Repair
RV: 2020 Thor Palazzo 36.2 • Location: Encore Fort Pierce, Site 71 • City:
Symptom: Owner converting from LP to park model natural gas hookup; Suburban SW10DE water heater producing yellow-orange flame and sooting around the burner cup after connection to the campground NG supply; NG supply pressure at the pedestal was 7.0 WC
Diagnosis: Jesse Earl confirmed the Palazzo was delivered with LP orifice (P/N 233600) in the SW10DE water heater - a 0.082-inch diameter orifice for LP at 11.0 WC inlet pressure. Natural gas at 7.0 WC requires a 0.148-inch diameter orifice (Suburban NG orifice P/N 232630) to deliver the same 10,000 BTU/hr heat input. Running LP orifice on NG produced only 36% of rated heat input, causing a yellow, incompletely combusted flame with CO production. Air shutter was set to LP position (40% closed) and required adjustment to NG position (20% closed) to match the higher-volume NG air requirement.
Outcome: Post-conversion flame pattern solid blue with 0.5-inch inner cone; no sooting; combustion CO measured at burner cup: 18 ppm (ASHRAE 62.2 threshold: 25 ppm at 50% excess air); water heater achieved 110 F outlet temperature within 18 minutes (spec: 20 minutes for 10-gallon tank)
Time on-site: • Total cost: • Dealer alternative:
LP vs. Natural Gas Conversion - Orifice Sizes for Common RV Appliances
| Appliance / Model | LP Orifice P/N (size) | NG Orifice P/N (size) | LP Inlet Pressure | NG Inlet Pressure | Rated BTU/hr |
|---|---|---|---|---|---|
| Suburban SW10DE water heater | 233600 (0.082 in) | 232630 (0.148 in) | 11.0 WC | 7.0 WC | 10,000 BTU/hr |
| Suburban SF-30 furnace | 161027 (0.062 in) | 161028 (0.108 in) | 11.0 WC | 7.0 WC | 30,000 BTU/hr |
| Dometic/Atwood 7916-II range | 90073 (0.055 in) | 90074 (0.093 in) | 11.0 WC | 7.0 WC | 9,000 BTU/hr (per burner) |
| Dometic RM1350 fridge (LP burner) | 291346750 (0.038 in) | 291346751 (0.064 in) | 11.0 WC | 7.0 WC | 1,600 BTU/hr |
| Atwood 8531 water heater | 91374 (0.075 in) | 91375 (0.130 in) | 11.0 WC | 7.0 WC | 8,800 BTU/hr |
Signs You Need Gas Appliance Conversion
- ✓Verify destination gas type and inlet pressure at connection point (LP: 11.0 WC; NG: 7.0 WC typical)
- ✓Identify all appliances requiring orifice swap - conversion is appliance-by-appliance, not system-level
- ✓Order correct replacement orifices for each appliance by manufacturer P/N before service call
- ✓Remove and replace main burner orifice with correct size for destination gas
- ✓Adjust air shutter to starting position for destination gas type
- ✓Light burner and verify blue flame with defined inner cone at all settings
- ✓Use combustion analyzer to verify 30-50% excess air (4-6% O2) in flue gas
- ✓Fine-tune air shutter to achieve target O2 reading
- ✓Measure inlet manifold pressure at appliance test port (must match regulator output)
- ✓Test all appliance safety systems (thermocouple, high-limit, sail switch) after conversion
- ✓Apply conversion label per ANSI Z21.1 to each appliance indicating gas type and orifice size installed
Gas Appliance Conversion - Pricing
Typical price range: $199 - $549
All calls start with a $299 service-call fee that covers the technician's trip to your location and the first hour of diagnosis. That $299 applies toward any repair you authorize - it is not an additional charge on top of the repair. Pricing shown is a national average range; your exact quote is provided in writing on-site before any work begins.
Gas Appliance Conversion - Common Questions
Straight answers from our gas appliance conversion service call log.
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More RV LP Gas Systems Services
Other specialized repairs under rv lp gas systems - all done at your location, no tow required.
Where We Provide Gas Appliance Conversion in Florida
Coast to Coast RV Repair runs gas appliance conversion jobs across these cities. Click your closest one for local-specific info, response times, and campground coverage.