Tips to prevent combine fires

No one wants equipment to go down during harvest, especially if it’s due to a combine fire.

To help manage and prevent a combine fire, Joshua Michel, Iowa State University Extension and Outreach Field Agronomist, recommends practicing several safety principles before and during harvest season.

“Look at your local forecast,” Michel said. “When dry conditions persist, windy conditions increase potential for combine and field fires. That’s especially true when winds are strong and humidity is low. There’s a lot of dry corn stalks and bean residue, things are dustier, and all it takes to start a fire is a spark from an engine, overheated bearing, or contact with the exhaust manifold.”

As technology advances, today’s combines are larger and more powerful, which means they generate more heat during operation. Fire needs two sources for combustion: heat and fuel.

“You can’t get away from the heat a combine generates,” Michel said. “That means we have to do a good job of removing the fuel source that’s near the heat. Keep that combine clean, especially around the engine compartment. Use a high-pressure washer or compressed air to get rid of caked on oil and grease. Get any crop residue and dust off. The cleaner you keep it, the less potential there is for fire.”

Other maintenance tasks that help reduce fire risk include checking coolant and oil levels every day, especially if the combine features an engine turbo charger. During operation, there may be wear and tear on some areas which could lead to an oil or coolant leak. 

“A good practice is to frequently blow off any leaves, chaff or plant material,” Michel said. “You could use a leaf blower if a pressure washer or compressed air isn’t available. It’s best to get that done at the end of the day. If you wait till morning, dew may make it more difficult to get the plant materials off the machine.”

In addition to clearing the exterior of the combine, search for plant material that wrapped up on the machine near bearings, belts, or any place where friction occurs since friction is what produces heat.

“Check the exhaust system and make sure nothing is leaking, including fuel, oil, any hoses,” Michel said. “Inspect and clean any recessed areas near fuel tanks and lines. I know I sound like a broken record but keeping the machine clean is the best way to prevent a fire.”

When it’s time to refuel, take 10 to 15 minutes to allow the combine to cool down. This reduces the risk for gasoline or diesel fuel volatilization and igniting fumes.

“Research suggests that, if we have dry conditions, which we see this year across much of the Midwest, coupled with wind speeds in excess of 20 to 30 miles per hour, combine and field fires are nearly inevitable,” Michel said. “As dry as the growing season has been, things dry out even more in fall. Producers may want to consider if they can delay harvest until we have some moisture on the ground.”

Michel notes that even a shower that brings a tenth of an inch of rain can help significantly reduce fire risk.

“Obviously, producers still need to get into the field, but whatever can be done to reduce the risk of fire will be beneficial,” Michel said.

Most farm equipment is covered by insurance, however, in today’s economy, obtaining necessary repairs or equipment replacement could be challenging and take a significant amount of time.

“Do all you can to prevent a fire,” Michel said. “Even if you think you smell something, it’s better to call for help first, then inspect to see what’s happening. No one will complain if they reach the field to find there’s no fire to put out or you’ve managed to control it with your fire extinguisher.”

— Funding for this educational article comes from the Central States Center for Agricultural Safety and Health and the University of Nebraska Medical Center.