Overheating Generator [Causes and Solution]

Last Updated: August 8, 2022
Affiliate Disclosure: As an Amazon & other affiliate, we earn from qualifying purchases at no extra cost to you.

Overheating is the most common reason for generators to fail. If you can control the temperature of your generator and avoid it, you should not have to spend money to get expensive repairs done. But how do you prevent the problem in this blazing hot weather?

There are several common reasons that generators can overheat, but most of them can be fixed before any damage is done. Common reasons for overheating are low oil pressure, bad fuel, poor air circulation, over-utilizing the generators wattage, or damage to the generator’s internal parts.

Many newer generators have temperature gauges and sensors that allow the generator to automatically stop working when it gets too hot. This prevents serious damage from happening.

There are many different things that can happen to a generator, but overheating doesn’t have to be one of them.

Causes of Overheating Generator

Coolant Is Too Hot

During operation, the engine’s ‘water pump’ circulates coolant through the radiator, where ambient air is blown through the radiator’s matrix to reduce the coolant’s temperature. Make sure the coolant is at the proper temperature. The radiator cap may be pressurized and extremely hot if you remove it.  You must take the necessary safeguards. If the coolant has overheated, it may also be extremely hot when the cap is removed, causing steam to leak out.

Reason the Coolant Is Hot

  • A malfunction in the coolant switch or a reading from the coolant sender that is too high will cause the controller to shut down the set if the temperature of the coolant exceeds a certain threshold. The coolant can be hot because:
  • Insufficient cooling of the engine coolant causes the coolant to become hotter and hotter until the coolant switch closes, forcing the engine to shut down. 
  • The air flow through the radiator matrix has been impeded by accumulated dust and oil, resulting in the same outcome as in above. This is when you should hire a professional radiator cleaner.
  • The coolant pipes are clogged and the radiator is rusted on the inside. Using the wrong coolant / water mixture, or using the wrong type of coolant, or forgetting to change your coolant at the recommended intervals might cause this.
  • The coolant may not be flowing because the ‘water pump’ has failed. You’ll need a new water pump in this situation. In this case, the coolant in the radiator may still be cool since the engine coolant cannot be pushed to the radiator.
  • When the engine heats up, the thermostat opens, allowing coolant to circulate around the radiator. You’ll need to replace the thermostat if the old one has malfunctioned. Because the coolant in the radiator cannot travel from the engine to the radiator, it may still be pretty cold.
  • Coolant level Low

If you’ve just added more coolant, the system’s coolant level may be too low and allowing the device to overheat. In this case, more coolant can be added after the air lock has been removed.

If the Coolant Is Not Too Hot, It Could Be Because

  • The thermostat, which opens when the engine warms up to allow air to circulate around the radiator, has malfunctioned. You’ll need to replace the thermostat if it’s broken.
  • The coolant may not be flowing because the ‘water pump’ has failed. A new water pump would be required in this situation.
  • The coolant switch gave the controller a false fault message.
  • The coolant sender is showing an excessive value.
  • A damaged cooling fans.
  • Checking the fuel injectors is a good idea. To compensate for a clogged injector, the system will be overworked and underpowered.
  • A clogged exhaust pipe prevents the engine from reaching its full potential.
  • In cases where the generator is unable to handle the demand. A generator might overheat if it is subjected to an uneven, unbalanced load.
  • Insufficient oil in the system.
  • Overheating can occur when the density of air drops as a result of rising temperatures, which reduces the amount of oxygen available for combustion and leads in a decrease in the engine’s power output.
  • The generator’s cooling system degrades as a result of the increased humidity. Since the coolant and exterior are similar, heat is hard to dissipate.

Damage from Overheating

The downtime and high maintenance expenses that come with broken generators are all too common when they overheat. Insulation and wire can soften, melt, and even catch fire when exposed to high temperatures. The voltage regulator in the generator is the most common component to fail.


How to Avoid Generator Over Heating Kept Inside a Building?

Consider the following factors:

  • In the generator housing area, there should be no restrictions on the movement of air.
  • Heat generated by the generator must be properly dissipated, or it will build up and eventually shut down due to excessive heat. Additionally, a 2-meter clearance should be maintained around the exhaust location.
  • You must also ensure that the DG set is not surrounded by any other equipment that could add to the buildup of heat surrounding the generator, so impeding the cooling system.
  • It’s also critical that we utilize high-quality fuel and coolant in our vehicles.
  • In accordance with the manufacturer’s instructions, regular maintenance should be carried out. In addition, preventative maintenance is essential. 

How Can I Tell if My Generator Is Overheating?

You can check the temperature of the generator using a temperature sensor or gauge. If it doesn’t, it may start making a lot of noise, emitting a lot of heat, or running in an intermittent manner.

Can I Spray Water on My Generator?

No. The structural integrity of the engine and generator elements might be damaged by spraying cold water on hot metal.

Water is usually not good for generators. If water is sprayed into the generator’s components, the connections could be damaged, allowing moisture to enter the fuel or fuel lines. As a result of water, the parts may become weakened. When the generator is running, any water that is still on or within it can electrocute the user.

How Do You Cool a Generator Down?

Turn off the generator and let it cool down. Use a fan to remove warm air from the room and allow fresh air to circulate. Ensure that nothing is obstructing the exhaust. Never mist your generator with water.

Can the Sun Cause a Generator to Get Too Hot?

On a sunny day with temperatures above 90°F, the metal of a generator can reach up to 120°F (or more). This can cause the generator to overheat when it is paired with the engine’s internal temperature. To keep the generator from overheating, use a tarp or a tent as a cover.

Read Next:

I am a mechanical engineer with years of experience working on Internal combustion engine and fixing electrical and mechanical systems, generators, transfer switches, and equipment related to storm water and sewage pumping stations.