Generator Will Not Start on Natural Gas – Troubleshooting Guide

If your generator will not start when using Natural Gas, follow the steps below to identify and resolve the most common causes.

⚠ Safety Notice:
Do not operate the generator if you smell natural gas before startup, as this may indicate a leak.

Step 1: Confirm Proper Startup Procedure

Make sure the generator is being started using the correct Natural Gas startup procedure.

(CLICK HERE) To Review Start up Procedures If Needed

Step 2: Verify Battery Connection

Generators are shipped with the negative battery terminal disconnected for safety during shipping.

Confirm that the battery is properly connected before attempting to start the generator.

(CLICK HERE) On instructions how to connect battery If Needed

Step 3: Test the Battery Voltage

If using the push-button start, check the battery voltage.

Recommended readings:

• 13.5 volts when not under load

• 11.5 – 12 volts under load

Recharge or replace the battery if the voltage is too low.

Step 4: Inspect Natural Gas Hose and Connections

Inspect the natural gas hose and fittings for:

• Damage

• Loose connections

• Signs of gas leaks

Also inspect the second-stage regulator, which is typically located behind the generator panel.

Step 5: Verify Natural Gas Supply Pressure

Confirm that your natural gas supply is producing the correct fuel pressure.

The required natural gas inlet pressure should be:

6.0 – 9.0 inches of water column (WC)

Insufficient or excessive pressure may prevent the generator from starting or running properly.

Step 6: Confirm Natural Gas Supply Capacity (BTU Requirements)

Your natural gas supply must provide enough BTU capacity to operate the generator at full load.

If the gas supply cannot meet the required BTU demand, the generator may fail to start or stall under load.

Step 7: Verify Fuel Selector Switch Position

Ensure the fuel selector switch is fully set to the Natural Gas position.

If the selector switch is not fully engaged, the generator may not receive fuel.

Step 8: Inspect the Spark Plug

Remove and inspect the spark plug for:

• Carbon buildup

• Damage

• Weak spark

Replace the spark plug if necessary using the NGK spark plug recommended for your generator model.

Step 9: Verify Choke Position

Confirm the choke is positioned correctly during startup.

Note: EH series generators use a manual choke.

Step 10: Test Other Fuel Sources

If possible, try starting the generator using gasoline or propane.

• If the generator runs correctly on other fuel sources, the issue may be related to:

  • Natural gas supply pressure

  • Fuel selector switch

  • Natural gas regulator or hose

Potential Parts That May Require Replacement

Based on troubleshooting results, one or more of the following components may require replacement.

Natural Gas Hose

Replace the hose if:

• Fittings are damaged

• Gas leaks are present

• The hose shows signs of cracking or wear

Second-Stage Regulator

Replace the regulator if:

• It is damaged

• Gas leaks are present

• It is not regulating natural gas pressure correctly

Fuel Selector Switch

Replace the fuel selector switch if:

• The knob or assembly is broken

• The switch cannot fully engage

• The generator runs when bypassing the selector switch

Natural Gas Fittings

Replace fittings if:

• They are damaged

• Gas leaks are present

• The fittings are not seating correctly

Generator Will Not Start on Any Fuel Source

If the generator will not start on gasoline, propane, or natural gas, check the following:

1. Inspect the electric start system

2. Confirm the generator attempts to crank

3. Check for spark

4. Verify the engine oil level

5. Look for any sensor warning lights on the control panel

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✅ Support Tip:
Most natural gas starting issues are related to insufficient gas pressure or BTU supply from the home gas line. Always confirm the gas supply pressure (6–9 in. WC) and BTU capacity meet the generator’s requirements.