Westinghouse iGen4000DFc Won’t Switch Fuels: Troubleshooting Guide

The Westinghouse iGen4000DFc dual-fuel generator is a workhorse for backup power and job-site use, but its fuel-switching system has a few quirks that catch owners off guard. If you’re trying to flip from gasoline to propane (or back) and the engine keeps running on the old fuel, or won’t start on the new one, you’re looking at one of five specific failure points—all of which you can diagnose yourself in about 30 minutes with basic tools.

At-a-Glance: Most Likely Causes

Diagnostic Walkthrough

Work through these steps in order. Stop when you’ve fixed the problem.

1. Stop the engine completely. This is non-negotiable. The fuel-selector switch on the iGen4000DFc only indexes safely when the engine is off. If you attempt to switch while the engine is running, the switch won’t fully engage and fuel won’t transfer. Turn off the engine, wait 30 seconds for it to cool, then proceed.
2. Inspect the fuel-selector switch for full engagement. Locate the switch on the control panel (typically a three-position dial or lever: Gasoline / Off / Propane). Rotate it firmly to your target fuel position. You should feel a distinct mechanical click or detent. If the switch feels loose, doesn’t click, or stops partway, it’s not fully indexed. Try rotating it again with deliberate pressure—sometimes a partial turn leaves it between positions. If it still won’t click, the switch may have internal wear and will need replacement.
3. Check the propane tank valve and pressure. Walk to your propane supply. Ensure the tank valve (the knob on top of the tank) is fully open—turn it counterclockwise until it stops. Next, listen for a faint hiss near the regulator or fuel line; a hiss means propane is flowing. If you hear nothing, the tank may be empty. Shake the tank gently; if it’s completely silent and feels light, it’s empty. Refill or swap the tank. If the tank is full but you still hear no hiss, the regulator may be frozen or the tank valve may be stuck—call a propane service to inspect.
4. Verify gasoline freshness and fuel-line integrity. If you’re switching back to gasoline and the engine won’t start or runs very rough, the gasoline may be stale. Gasoline older than 30 days can gum up the carburetor. Drain the old fuel into a safe container (use a siphon pump or drain plug if available), then refill with fresh gasoline containing fuel stabilizer. While you’re at it, inspect the gasoline fuel line for cracks, kinks, or loose fittings. A cracked line will leak fuel and prevent proper flow.
5. Listen for solenoid valve clicks when switching. With the engine off and the fuel selector in the Gasoline position, turn the ignition key to the “On” position (do not start the engine). You should hear a faint clicking sound from the fuel solenoid valve (located near the carburetor or fuel pump). This click means the solenoid is energized and opening the fuel circuit. Now rotate the selector to Propane while the ignition is still on. You should hear another click as the solenoid switches circuits. If you hear no clicks at all, the solenoid is not receiving electrical power—check the wiring and battery voltage (see step 6). If you hear a click but the engine still won’t run on that fuel, the solenoid plunger may be stuck internally.
6. Check the battery voltage and electrical connections. The fuel solenoid requires 12V DC to function. Use a multimeter to test the battery: set it to DC volts and touch the red probe to the positive battery terminal and the black probe to the negative terminal. A healthy battery reads 12.6V or higher. If it reads below 11V, the battery is weak and won’t power the solenoid reliably. Charge or replace the battery. Also inspect the battery terminals for corrosion (white, blue, or green crusty buildup). If corroded, disconnect the terminals, clean them with a wire brush, and reconnect firmly.
7. Test fuel flow at the carburetor inlet. If you’ve confirmed the solenoid is clicking but the engine still won’t run on the selected fuel, fuel may not be reaching the carburetor. Locate the fuel line inlet on the carburetor (consult your owner’s manual for exact location). Carefully disconnect the fuel line at the carburetor and position it over a small container. Turn the ignition on (without starting the engine) and select the fuel you want to test. You should see fuel dribble or spray from the line within 5 seconds. If nothing flows, the fuel pump or solenoid is blocked, or the tank is empty. If fuel flows freely, reconnect the line and try starting the engine.
8. Perform a full fuel-switch cycle with a fresh start. Once you’ve worked through the above steps, shut off the ignition and let the engine sit for 2 minutes. Then select your target fuel, start the engine, and let it run for 30 seconds on that fuel. Listen for smooth operation and check for any unusual odors (a strong propane smell or gasoline smell when the other fuel is selected suggests a leak). If the engine runs smoothly and the fuel smell matches your selection, the switch is working. If not, return to step 5 and recheck the solenoid.

Parts You May Need

• Fresh gasoline (with fuel stabilizer)
• Fuel solenoid valve (if internal failure is confirmed)
• Fuel-selector switch (if mechanical engagement fails)
• 12V battery (if battery voltage is below 11V)
• Propane tank refill or swap service
• Carburetor rebuild kit (if stale fuel has caused gumming)
• Fuel line and fittings (if cracks or leaks are found)

When to Call a Pro

Stop troubleshooting and contact a small-engine technician or authorized Westinghouse service center if:

• The fuel-selector switch does not click or fully engage after firm rotation, and you cannot manually move it to a detent position.
• You hear no solenoid click when the ignition is on and the selector is moved, and the battery tests at 12.6V or higher with clean terminals.
• Fuel flows to the carburetor but the engine will not start or run on the selected fuel after two or more restart attempts.
• You smell gasoline or propane leaking from the fuel lines, regulator, or solenoid housing.
• The engine runs on one fuel but not the other, and you’ve confirmed the tank is full, the valve is open, and the solenoid is clicking.

Frequently Asked Questions

Can I switch fuels while the engine is running?

No. The fuel-selector switch on the iGen4000DFc is designed to work only when the engine is off. Attempting to switch while running will prevent the switch from fully indexing to the new fuel circuit, and the engine will continue running on the old fuel. Always stop the engine, wait 30 seconds, and then rotate the selector firmly to the new position.

Why does my propane tank feel empty but the valve is open?

Propane tanks can appear empty for two reasons: the liquid propane inside has been fully consumed, or the regulator has frozen due to moisture or cold weather. If the tank is truly empty, you’ll need a refill. If the tank is full but the regulator is frozen, a propane service technician can thaw and inspect it. Never attempt to heat a propane tank yourself.

What does a fuel solenoid click sound like?

A solenoid click is a sharp, brief metallic sound—similar to a relay clicking in a car’s electrical panel. It lasts less than a second and comes from the solenoid body near the fuel pump or carburetor. If you hear nothing when the ignition is on and the selector moves, the solenoid is not receiving power or has failed internally.

How long can gasoline sit in my generator before it goes bad?

Gasoline begins to oxidize and gum up after about 30 days of storage, especially in warm conditions. If you store your generator for more than a month, use gasoline with a fuel stabilizer additive, or drain the tank before storage. Stale fuel will cause hard starting and rough running on gasoline mode.

Disclaimer

This article provides general troubleshooting guidance for the Westinghouse iGen4000DFc dual-fuel generator. Always consult your model-specific owner’s manual for detailed procedures, safety warnings, and component locations before attempting any repairs. If you are unsure about any step, contact an authorized Westinghouse service center or a qualified small-engine technician. Improper fuel handling or electrical work can result in fire, explosion, or injury.

Source: Information adapted from official manufacturer documentation (reference). Always consult your generator owner’s manual for model-specific procedures.