How to Fix an Inverter Cooling Fan Not Working

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Inverters generate heat when DC (direct current) is converted into AC (alternating current). A cooling fan keeps the components from overheating so it is essential the fan is working. Here are the common causes of inverter cooling fan failure and the solutions.

Inverter cooling fans run when the inverter is charging a battery or loading appliances, and if there is insufficient power the fan will stop working. Cleaning the fan, increasing battery power or tightening loose wires will fix the problem.

Not Enough Power

Solar inverters are usually run by a battery bank or shore power. If there is not enough power getting through, the fan will eventually cease to run.

Most inverter fans do not run all the time. Most of them turn on when the inverter is charging a battery. The fan also turns on when the system powers a load.

Solution: make sure there is enough power for the inverter to run. Inverter power requirements depend on how much load it carries, not its capacity.

If you have a 3000 watt inverter like the PD3000 and it carries a 2000 watt load, you need 2000 watts power, not 3000. You might want to add another 10% to the required amount so there is cushion in case of sudden power spikes.

To convert watts into battery amp hours, divide the watts by the battery voltage. So if you are running a 2000 watt power load, get a 12V 200ah battery.

Always round off the battery to the next biggest size available. There is no such thing as too much battery reserve power. The more power the battery has, the longer you can run the fan and inverter load.

Inverter Overload

One of the most likely reasons is system overload. If the inverter load is is greater than its capacity, there won’t be enough energy to power the fan and other components.

Inverter load capacity is expressed in watts so it is easy to determine its appliance capacity. But due to inefficiency, inverters should never be loaded at full power. Doing so will overload the system and cause components like the cooling fan to malfunction.

Solution: If you have a 3000 watt inverter, the maximum load should be 2800 watts, 2500 is better. Some even recommended you double the inverter size for your required capacity.

You can tell if a cooling fan is dealing with overload by listening to it. These fans should run quietly, but if it makes a lot of noise, that is a sign there is an overload or other system issues.

Overloading and insufficient power are related. If you overload the system the fan will not be able to cope with the heat. Reducing the load or adding more batteries will definitely help.

Overheating / Too Cold

Inverters are designed to run within a temperature range, usually -13F to 140F (-25C to 60C). It is unlikely your inverter will ever reach these extreme temperature ranges, but there is more to this.

Inverters have an optimum temperature working range. Even if it does not reach 140F or -13F, cooling fan performance will slowly deteriorate when it gets too hot or too cold.

If the inverter runs outside the ideal temperature range, derating occurs. The system reduces its output to safeguard the components.

Solution to Overheating: read the instructions. It contains information on proper usage and protection against overheating.

Inverters should be installed in shade. You can place it near a wall but there should be space between the inverter and the wall.

Inverters are best installed inside. Do not expose the inverter to sunlight if you have to install it outside.
Ventilation is key. Give the inverter room and this will make it easier for the fan to work.

Solution to Cold: Cool weather is generally favorable for cooling fans. But if it is too cold there could be issues. Keeping the inverter in moderate temperature is ideal.

If your inverter is installed outside, bring it indoors before winter comes. Intense cold might freeze the fan and other components.

Battery Problems

Any problem with the battery will affect the cooling fan. If there is nothing wrong with the inverter, check the battery. Here are some common problems.

  • Battery does not charge
  • Blown fuse
  • Damaged rectifier
  • Loose wiring
  • Dead battery
  • Corrosion
  • Reversed battery terminals

Solution: check the battery cable and make sure that it is secure. Give it a bit of a tug. Look for signs of wear and tear. Replace the wires if necessary.

  • Replace the battery if it is corroded, dead, too weak to carry a charge or just unusable.
  • If the terminals are reversed, adjust accordingly.
  • Replace any blown or melted fuses.
  • An old battery will not carry a charge the way a new battery does. If the battery starts losing power quickly, better replace it with a new one.

Ensure the battery has sufficient charge to carry the load. If there is not charge, the inverter fan will not run properly and there might not be enough power to start the load.

Wiring Problems

Cables and wires hold an inverter system together. A loose connection can slow down or prevent the system from running. It will not just be the fan but the entire inverter.

Even if the wires are secure they might already be frayed. These should be replaced because they could cause problems later on.

Solution: make sure the inverter cable is the right length and properly connected. You should also check the cables for the charge controller and solar panels. If any are loose it will disrupt the system.

Inverter Fan is Damaged

If the fan is making a lot of noise and suddenly stops running, it could be damaged. First you should consider all the possibilities. The fan might be noisy because it is doing a lot of work. A heavy load requires a lot of conversion, so it is natural for the fan to run a higher speed.

Solution: If the fan refuses to run, check if it needs cleaning. If that does not work, check the battery if there is enough power available. Look at the connections too.

if the inverter is still under warranty, have the fan repaired or replaced. If the warranty has expired, it is better to buy a new fan than repair the old one. The GDSTIME 12V DC Cooling Fan is compatible with various inverters.

Frequently Asked Questions

Does an inverter fan run all the time?

Inverter cooling fans usually cycle on and off. The fan comes on when the inverter starts up and during the DC to AC process. But it is normal for the fan to turn off automatically.

Why is my inverter fan not working?

There are many possible reasons such as system overload, dirt, overheating, loose wires and so on. Refer to the guide above for possible solutions.

My inverter cooling fan is under warranty. Should I attempt to fix it?

Do not tinker with the fan because it will void the warranty. You should only clean the fan as directed in the instructions. Do not disassemble the fan or any of its components.

My inverter cooling fan is no longer under warranty. What should I do?

Take the inverter to where you bought it. They can determine if the fan can still be fixed or not. In some cases it is possible. In others, it is better to get a replacement.

Can I replace the inverter fan?

Replacing the fan will probably void the warranty. This also requires knowledge of how inverters work. If you are not familiar with it, this could damage other components.

Is it normal for an inverter cooling fan to make noise?

These fans generate sounds, but usually it is negligible. A loud whirring noise indicates there is a problem. It could be dirt buildup or the load is too much for the fan to handle.

Is it safe to run an inverter cooling fan outside?

You can install and run inverters outside without any problems. But they will be exposed and affected by the elements. To avoid this, install the inverter indoors or put up a roof over it.


If your inverter is still covered by the warranty period, you can have the fan repaired or replaced. If the warranty has expired and the solutions above do not work, it might be time to buy a replacement.