Sunstar · Fuel & Conversion
Sunstar Natural Gas vs Propane: Manifold and Supply Pressures
Sunstar heaters run on either natural gas or liquid propane, but each fuel needs specific supply + manifold pressures. Running the wrong pressure damages the burner and voids the 3-year warranty.
By Ash · Updated November 10, 2026
What you need
- Manometer (gas tech)
- Supply-line pressure gauge
MGL35 fuel + pressure spec (representative Sunstar numbers)
- Natural gas manifold pressure — HIGH
- 6.0" W.C.
- Natural gas manifold pressure — LOW
- 2.8" W.C.
- Natural gas supply pressure
- 7" to 14" W.C.
- Propane manifold pressure — HIGH
- 11.0" W.C.
- Propane manifold pressure — LOW
- 5.0" W.C.
- Propane supply pressure
- 11.5" to 14" W.C.
Step by step
Confirm which fuel you're set up for
The spec label on the heater reads either 'NG' or 'LP'. If it's wrong for your supply, you need the conversion kit from AEI Corporation — call (949) 474-3070.
Measure your supply pressure
Natural gas needs 7-14" W.C. supply. Propane needs 11.5-14" W.C. A gas tech measures at the tee closest to the heater. Low supply = bad flame; high supply = regulator failure risk.
Set the manifold pressure to spec
Natural gas HIGH stage = 6.0" W.C. manifold. Propane HIGH stage = 11.0" W.C. manifold. Adjust at the heater's regulator. This is a licensed gas-fitter task, not DIY.
Confirm the low stage
Two-stage output means the LOW setting also has a manifold pressure spec (2.8" W.C. natural gas, 5.0" W.C. propane). Verify both stages match spec before closing up the install.
Leak-test every joint
Soap-bubble solution on every joint after install. Any bubbling = leak = tighten + retest. Never use a flame to leak-test.
Common mistakes
- Running a NG-rated Sunstar on a propane tank. Propane is ~2x the heating value of natural gas by volume. Running NG orifices on propane overheats the burner, damages the firebox, and makes a lot of dangerous combustion byproducts. Different orifice + different regulator = conversion kit required.
- Teeing off a kitchen gas line. Patio heaters typically need dedicated or properly-sized shared gas lines. Teeing off an existing appliance line without resizing can starve both appliances when running simultaneously.
Hands-on tips
- Natural gas = tied to utility supply. Reliable, cheaper per BTU, requires a gas-line install. Propane = tank-based, works anywhere, slightly higher per BTU cost.
- Order the conversion kit before the install if you're switching — kits have limited stock + 1-2 week lead times.
Questions people ask
Can I switch my Sunstar from LP to NG myself?
No. The conversion requires replacing the orifice, regulator settings, and possibly the valve. Factory conversion kit + licensed gas fitter are both required for a safe + warranty-preserving conversion.
Why are the manifold pressures different for NG vs LP?
Propane has roughly 2x the energy density of natural gas by volume. To get the same BTU output, propane runs at higher manifold pressure through a smaller orifice. That's why you can't just flip a valve to switch fuels.
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