RV Generator Service & Repair
Your RV generator is the backbone of your power system when shore power isn’t available. When it won’t start, runs rough, surges under load, or shuts down unexpectedly — everything stops with it. Professional RV generator repair is the difference between a rig that’s ready and one that strands you at a campsite with no AC.
Generator problems are one of the most common calls we get, and they’re almost always diagnosable and repairable on-site. United Mobile RV LLC provides mobile RV generator service and maintenance for the most common brands and platforms — with proper diagnostic equipment and the mechanical background to go beyond the basics. We come to you anywhere in Washington — driveway, storage lot, or campground.
Generator Service — Brands We Work On
From built-in coach generators to portable units, we diagnose and repair the platforms RV owners actually run.
Onan
The most common RV generator brand by a wide margin. Onan QG, QD, and Marquis series gasoline and LP generators are found in the majority of Class A, Class B, and Class C motorhomes. Onan diagnostics, fault code reading, and repair is core to what we do.
Generac
Found in a range of motorhomes and increasingly in portable RV generator setups. Generac RV generators share many service points with Onan units and we handle them accordingly.
Kohler
Less common in RV applications but found in premium motorhomes. Kohler RV generator service follows the same diagnostic approach as other platforms.
NPS — Next-Gen Power Systems CERTIFIED TECH
NPS generators run Yamaha engines with pure sine wave inverter technology — quiet, efficient, and safe for sensitive electronics. Available in ECO, EFI, and propane configurations with a 3-year / 2,000-hour unlimited warranty. We are NPS certified technicians and can service, diagnose, and repair the full NPS generator line on-site.
Portable Generators
Honda, Champion, Westinghouse, and other portable generators used alongside or in place of built-in units. Carburetor service, fuel system issues, and basic electrical faults on portable units are within scope.
What Our Generator Repair Service Covers
No-Start Diagnosis
We work through fuel delivery, ignition, choke operation, starter function, and control board signals systematically to identify the actual cause. Common no-start issues include carburetor fouling from ethanol fuel, stuck choke valves, failed fuel pumps, and control board faults — all diagnosable and most repairable on-site.
Surging & Unstable Output
A generator that surges at idle or under load, produces unstable voltage, or hunts for a stable RPM is usually a carburetor or governor issue. Carburetor cleaning and rebuild, governor adjustment, and fuel system inspection resolve the majority of surging complaints.
Overload & Shutdown Under Load
If your generator starts fine but shuts down when you turn on the AC or add a significant load, the cause is typically low output voltage, a failing AVR, carbon brush wear, or an overloaded circuit. We test output voltage and frequency under load to isolate whether the problem is in the engine side or the generator head.
Oil & Fuel System Service
Generator oil changes, air filter replacement, spark plug replacement, and fuel filter service. Generators that sit for extended periods develop fuel system issues from stale fuel and ethanol degradation. A proper fuel system service resolves the majority of generator problems that develop over winter storage.
Carbon Brush & AVR Service
The carbon brushes and automatic voltage regulator are wear items inside the generator head that affect output quality and eventually cause failure if neglected. We inspect and replace these components as part of generator service on units with accessible brush assemblies.
Control Board Fault Code Diagnosis
Onan and other modern RV generators log fault codes that identify the nature of a shutdown or operational problem. We read and interpret these codes in context — a code points toward a system, proper diagnosis tells you the actual failed component.
Exhaust & Mounting Inspection
Generator exhaust leaks inside a motorhome are a carbon monoxide hazard. We inspect exhaust connections, muffler condition, and compartment sealing as part of any generator service visit. Generator mounting hardware and vibration isolator condition are checked as well.
Generator Service & Maintenance Schedules
RV generators are notorious for developing problems from sitting — far more than from actual use. Ethanol-blended fuel breaks down, gums up carburetors, and leaves deposits that cause hard starting and surging. A generator that ran perfectly last fall may not start next spring without some attention.
Annual Service
Oil change, air filter, spark plug, fuel filter, and a full operational test under load. This is the baseline that keeps a generator reliable season to season.
Pre-Storage Service
Fuel system treatment or carburetor drain before extended storage significantly reduces the chance of fuel-related problems when the unit comes back out.
Post-Storage Start-Up
If your generator has been sitting for a season or more, a proper inspection and fuel system service before you rely on it is worthwhile. Finding out it doesn’t work on a 95-degree day at a campground with no shore power is not the time.
Load Testing & Output Verification
A generator that starts and runs doesn’t mean it’s producing clean, stable power at the correct voltage and frequency. We test output under actual load conditions — not just at idle — to verify your generator is producing what your RV’s systems require. Incorrect output voltage damages sensitive electronics, inverter/chargers, and appliances over time.
Generator Service Questions We Get a Lot
How much does RV generator repair cost?
It depends entirely on what’s wrong — a fuel system service and annual maintenance run far less than a carbon brush or AVR replacement. Because we diagnose on-site before doing any work, you get an actual number for your specific problem instead of a guess. See our pricing page for a general sense of service call rates.
Why won’t my RV generator start?
The most common causes are stale or ethanol-degraded fuel gumming up the carburetor, a stuck choke, a failed fuel pump, or a control board fault code the generator is reporting but you can’t see without a proper diagnostic read. Generators that sat all winter without a fuel system treatment are the single most common no-start call we get every spring.
Why does my generator shut down when I turn on the AC?
That’s a classic overload-under-load symptom — usually low output voltage, a failing AVR, worn carbon brushes, or a genuinely overloaded circuit. We load-test output voltage and frequency to isolate whether the fault is on the engine side or inside the generator head before recommending a repair.
Do you work on Onan, Generac, and Kohler generators?
Yes — Onan is the most common RV generator brand we service, followed by Generac and Kohler. We’re also NPS certified technicians for the full NPS generator line, plus portable units from Honda, Champion, and Westinghouse.
Do I need a full generator service if it’s been sitting all winter?
A post-storage inspection and fuel system service is strongly worth doing before your first trip of the season — it catches the fuel gumming and hard-starting issues that develop from sitting, before they strand you at a campground with no shore power.
OUR GENERATOR PICKS
Generator service parts & portable picks
OEM air filter for Onan QG 4000-series gensets
OEM oil filter for Onan RV gensets
Cuts A/C startup surge so the genset or a portable can run it
Quiet 2,200W inverter generator for rigs without a built-in genset
2,200W inverter with fuel gauge and CO shutoff
Gas or propane, with a TT-30 RV outlet built in
Want it installed? We do that. Request an Appointment · Remote consult · All our generator picks →
As an Amazon Associate we earn from qualifying purchases.
Ready to Schedule Generator Service?
We come to you — campsite, driveway, or storage facility. Book online or call and we’ll get it sorted.