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Generator Troubleshooting Guide

Buying a diesel generator gives you a long-term solution for all your power requirements. Whether you need prime power for off-grid operations or want a reliable standby electricity source for business or residential use, generators offer many benefits.

Routine maintenance usually keeps your generator at optimal performance, but malfunctions can occur. These malfunctions are generally easy to fix – we’ll reveal how in our generator troubleshooting guide.

The problems we’ll cover:

  • Generators that won’t start
  • Failure to produce power
  • Generators that won’t turn over
  • Sputtering generators
  • Top generator maintenance tips

The diesel generator won’t start

My generator tries to start and the engine is rotating and cranking but it won’t fire and run

Whether you’re trying to turn it on manually or the ATS (automatic transfer switch) won’t activate, some problems can usually be easy to fix yourself. Following these steps can help you identify the problem and fix it:

  • Fuel tank checks: First, check if your generator needs more fuel. It’s one of the most common generator problems, and you can fix it by adding more diesel.
  • Oil checks: Generators should have clean engine oil that aligns with the manufacturer’s recommendations. You can use a dipstick to assess the oil and change it if necessary.
  • Battery checks: If your battery is low or flat, the generator will struggle or not start at all.
  • Start and choke valve switches: If the main control switch is off, you’ll need to change it on. When starting the generator, the choke valve must be closed and switched to open once warmed up. (Petrol generators only)
  • Spark plug assessment: Spark plugs naturally degrade over time, and you might need to replace the ignition coil. An ignition spark tester can determine whether the plug receives an electrical current. In some cases, you can clean the plug’s components, but if there are signs of degradation, it’s time for a replacement. (Petrol generators only)
  • Carburettor and fuel valves: If the generator won’t start, it’s often due to blocked fuel valves or carburettor issues. Check both components for blockages and clogs, and clean both accordingly. Blockages are common when the diesel generator won’t start- but most are easy to remove. (Petrol generators only)
Generator Battery Testing

Generator Battery Testing

The generator runs but isn’t producing power

When a generator runs but won’t produce power, it’s often due to a loss of residual magnetism or a failed automatic voltage regulator. The magnetism residual remains after you use a generator, which provides it with electricity to start up, resulting in a continuous cycle.

However, the generator can’t produce electricity without residual magnetism. For this issue, it is best to seek help as this will require electrical testing of the alternator components to determine the fault.

Other causes of no power include:

  • Issues with the automatic voltage regulator and circuit breaker
  • Poor connections
  • A lack of maintenance

Learn how to fix a generator not producing power in our handy guide.

Generators that don’t turn over

Generator engines must rotate and crank to start – also known as turning over. When they fail to do this, you won’t be able to receive any power.

A generator that cranks but won’t start can occur for numerous reasons, including:

  • Faulty recoil starters: The recoil starter connects with the crankshaft, turning over the engine. If the starter is defective, it won’t form a proper connection. You can fix this issue by replacing it.
  • Battery issues: The generator battery can lose its charge over time – especially when you don’t use it regularly. Attempt to recharge it and see if the engine kicks in. If not, you might require a replacement battery.
  • Broken flywheels: Your generator’s flywheel is a vital mechanism that stores rotational energy. The engine won’t turn over properly when it’s broken, and you’ll need a replacement.
  • Clogged fuel filter: Generator fuel systems are complex mechanisms that can experience blockages from time to time. If the filter is blocked, it won’t allow fuel to flow through the system. In most cases, you can clean it to remove the blockages, but a replacement might be best.

Generator Fuel Filter

Sputtering generators

Does your generator make a sputtering noise or stall when operating? Not only is this annoying, but it can also disrupt operations. According to an article published by Accounts and Legal, IT downtime costs businesses up to £3.6 million annually – but generators should ensure your equipment remains operational.

If the generator is making a sputtering noise, it’s telling you something’s wrong. Potential causes include:

  • The electrics: Turn off all electronic devices and plugs connected to the generator, then turn it on again to see if the noise stops.
  • Clogged air filters: If the air filters are clogged, the carburettor won’t get enough air, resulting in the characteristic sputtering sound. Ensure you clean the air filters regularly and consider a replacement if you work in a dusty environment.

The generator is overheating

Overheating can cause significant damage to the generator’s components, and it often happens when the cooling mechanisms don’t work correctly. Our diesel generators come with instant alerts informing you of cooling system malfunctions.

It’s essential to switch the generator off and check for the following issues: 

  • Corrosion and build-up: When the generator’s elements begin to corrode or accumulate debris from a lack of cleaning, it can block heater hoses, preventing them from working. Extreme temperatures can also compromise block heaters, so they can’t cool the engine.
  • Air pockets: If your generator’s cooling system has air pockets, they can impact the circulation, leading to overheating. Bleeding the system should fix the issue, but if it still doesn’t work, you might need to check the fan motor to see if it’s functioning correctly.
  • Coolant leaks: Leaks are usually easy to spot, as you’ll notice signs around the hoses, radiator and water pump. You can fix the issue by replacing heater hoses and other faulty components.

Fuel leaks

Diesel fuel leaks can compromise the safety of your employees and cause significant damage to the generator. If you notice fuel leaking, fixing the issue immediately is essential. The leading causes of fuel tank leaks include:

  • Faulty lines: As with all components, fuel lines can experience wear and tear over time. When this happens, they cannot hold diesel, and you’ll notice it leaking through the line.
  • Damaged components: Over time, the fuel tank, connections, seals, and pump can degrade due to poor maintenance and corrosion. Check them for damage regularly and replace them if necessary.

Simplify generator maintenance with these top tips

Whether it’s a residential or commercial generator, regular maintenance will ensure a reliable supply of prime and standby power. Most generator issues are preventable, and these tips will help you enjoy a seamless experience.

  • Use the generator regularly: Prevent a dead battery by starting the generator regularly. Turning it on every two weeks will prolong its lifespan and ensure you can access power when needed.
  • Choose wisely: Buying a cheap generator might seem like a good idea, but it will cost more in the long run. Investing in a new generator from a reputable supplier gives you peace of mind and a longer service life. Discover what to consider when buying a diesel generator.
  • Maintain fuel levels: Ensure there’s enough fuel before starting the generator, and make sure you replace it every month. If you’re storing the generator, thoroughly empty its fuel tank to promote health and safety.
  • Clean the spark plugs and filters regularly: Guidelines suggest that spark plugs should be cleaned after 300 hours of usage, but we recommend cleaning them after 100 hours. The air filters also require frequent cleaning, but they might need replacing.
  • Remove debris from the components: Corrosion and debris build up can cause the generator to malfunction. Using a wire brush to clean the battery terminals and other components can prevent sputtering noises.
  • Oil level maintenance: The engine requires optimal oil levels to start properly. If they’re low, it can cause engine damage, resulting in expensive repairs. Be sure to check them before using the generator and top up accordingly.
  • Store the generator properly: Diesel generators should always be stored properly, away from high temperatures and moisture.
  • Use a professional maintenance service: Using a professional diesel generator servicing and repair company gives you regular maintenance and convenient repairs. Our professionals will assess your generator regularly, checking for common problems and preventing permanent damage.
Generator Fuel Tank Level Gauge

Generator Fuel Tank Level Gauge

Make generator malfunctions a thing of the past

Whether it’s simple human error or issues with the generator’s components, our troubleshooting guide helps you identify malfunctions and take steps to remedy them. Newer generators are less likely to experience problems, making them a sound investment for residential or commercial needs.

Solent Power is an authorised supplier of diesel generator sets, and our models come from the most reputable manufacturers. We offer an installation service, ensuring your generator has enough space to work and assessing all components when installing it.

Our professional team of experts also offer a maintenance and servicing package, meaning you don’t have to lift a finger. 

If you want a new diesel generator, please speak to our sales specialists today—we’ll help you find the right model for your needs and budget.

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