How Much Does It Cost to Repair a Generator Yourself?
Given generator installation costs between $2,000 and $15,000 (or more), maintaining and repairing your investment pays off in the long run. Standby generator repairs (whole-house or partial) are typically jobs for professionals. These devices contain many technical parts and, without the right expertise, diagnosing and fixing the problem will be a real challenge. You risk doing further damage and ending up with an even more costly repair bill when you admit defeat and call in the pro. Plus, because they often run on natural gas, there are safety risks to consider too.
For smaller, more basic portable generators, you may be able to troubleshoot and fix simple problems by topping up the fuel, unclogging filters, or tightening spark plugs. Generator fuel for 24 hours will cost you $30.
How Much Does It Cost to Repair Generators by Type?
Smaller portable generator repairs are, unsurprisingly, less costly than those required for a larger whole-house unit.
Portable Generators
Portable generators are designed to power a couple of appliances for just a few hours at a time. The mechanics of portable generators are much less complex than permanent standby installation, and the repair costs are considerably less.
Sometimes you may even be able to fix something simple yourself, and, on average, you won’t have to shell out much more than $50 for a professional generator repair plus any associated call-out fee (which typically ranges from $80 to $150).
Standby Generator
The average cost to repair a standby generator is around $600, but this can vary considerably depending on the generator power, model, and type of repair required.
How Much Does Generator Repair Cost by Part?
Often a specific part will cause a problem with your generator, and a technician will need to diagnose what it is and whether it needs repairing or replacing. Below are examples of the average costs to repair or replace some common generator parts.

Stator and Rotor
The moving rotor sits inside the stationary stator. You can expect to pay between $250 and $1,500 for replacement or rewinding of these pieces of equipment, depending on the size and style of generator you have.
Carburetor
A vital part of your generator’s mechanics, the carburetor mixes fuel and air for the required combustion process. Sometimes it may only need a minor repair, such as fixing a loose gasket, and cost around $50. For a complete carburetor replacement, you could pay anything from about $60 to $500.
Engine
You need to keep your generator’s engine ticking over well for smooth operation. Like the carburetor, a small repair may not involve spending much more than $50. Significant repairs or a complete engine replacement could end up costing you upwards of $2,000.
Voltage Regulator
Automatic voltage regulators (AVRs) are vital for ensuring the voltage output remains consistent. This is especially important when you have many major appliances connected to your generator. The part isn’t too expensive, typically not more than $80, and then you’ll also have the technician's labor costs.
Transfer Switch
All standby generators need a transfer switch to ensure that the mains power does not come into contact with the generator. Repairs are possible and typically cost around $50 to $150. If a switch requires replacement, it’ll usually cost between $200 and $400 for the part and then another few hours of labor costs as this is a detailed job.
What Factors Influence the Cost to Repair a Generator?
It isn’t just the type of part that can affect the cost of generator maintenance and repairs. Other factors can cause considerable variation.
Generator Power
Measurement of the power of a generator is in kilowatts. This can range from 10kW portable varieties to 45kW whole-house standby generators. Powerful large models have more complex engineering, and the cost to repair them will be more.
Fuel Type
Different fuel types power generators. Propane and natural gas generators may be more reliable and less likely to require repairs, but the cost to fix them is typically more when they do break down. Gas and diesel-powered generators require more upkeep, and repairs are usually more frequent.
Type of Repair
Because standby generators are complex pieces of machinery, there are many mechanical and electrical parts that can fail. How much a repair will cost will differ depending on what fails.
As well as the parts outlined above, other problems that require a technician to resolve them include:
Battery problems
Overfilled tanks
Spark plug issues
Coolant, fuel, or oil leaks
Fuel gauge malfunctions
Air bubbles
Coolant temperature and level problems
Annual Generator Maintenance
Annual maintenance checks will keep your generator running optimally and reduce the requirement for major repairs. An experienced service technician will make sure the generator has the correct levels of lubrication, fuel, and coolant. They’ll also check things like the engine filter, the battery or starting mechanism, and run tests on the transfer switch and voltage output.
Many reputable generator manufacturers offer annual service contracts. Depending on the generator you have and the checks carried out, you can expect annual generator maintenance costs to be around $150 to $300.