Ironwood 885 Firebox Catching On Fire

[CMack]

I've had my Ironwood 885 for just over two years now, and recently had issues with my firebox catching on fire. I start the Traeger and the temperature climbs rapidly and above the target temperature (i.e. 225 degrees) until the firebox catches fire. I removed and cleaned the auger after the first time that this happened, but no luck. Any help will be appreciated!

 

[RayClem]

What exactly do you mean? The firepot should catch fire shortly after igniting the grill and stay burning until you shut down the grill.

Do you mean that you are getting a back burn in the auger tube and pellet hopper?

Do you mean that the controller is no longer adjusting the flow of pellets and air properly to maintain the temperature?

More details might be helpful in diagnosing the problem?

 

[CMack]

What exactly do you mean? The firepot should catch fire shortly after igniting the grill and stay burning until you shut down the grill.

Do you mean that you are getting a back burn in the auger tube and pellet hopper?

Do you mean that the controller is no longer adjusting the flow of pellets and air properly to maintain the temperature?

More details might be helpful in diagnosing the problem?

Thanks Ray, I appreciate the quick response and will do my best to provide additional detail. I start the Traeger and set the temp to 225. As it goes through the ignition process the temperature starts climbing very rapidly, and quickly exceeds the target tem of 225. The firebox goes up in flames (it appears that there are way too many pellets in it) and the grill exceeds safe temps and tries to shut down. I then have a firebox almost half full of pellets in flames and have to snuff out the fire so that I can dig them out later.

 

[RayClem]

The details help.
Do you know if your controller has the most recent software? You have to have an active WiFi connection for this update to occur. I know that mine updated the first time I connected it to WiFi.

If you clean out the fire pot completely, you can use the auger priming button to add sufficient pellets to the box for it to ignite properly. During a normal cook (which is not happening with your grill), the final step is to do a grill shutdown sequence which allows the grill to burn for an additional 20 minutes or so such that most of the pellets in the burn pot are consumed.

When you say that you set your grill to 225F, does that mean the controller is set to 225F or to the setting that produces a temperature of 225F? The reason I ask is that the Traeger RTD temperature probes are notoriously inaccurate. With my IW885, I set the controller to 230F to achieve a temp of 225F, but I have to set the controller to 450F to achieve a temp of 400F.

I would suggest this as a troubleshooting procedure.

1. Remove the grates, drip tray and heat shield from the grill.
2. Vacuum out all pellets and ash from the grill.
3. Use the auger prime function to put a charge of pellets into the pot. Then look into the pot to make sure the igniter rod is covered, but the burn pot is not full.
4. If all looks well, try starting the grill without replacing the shield, drip tray and grates. Leave the grill lid open so you can observe exactly what is happening in the burn pot.
a. Is the hot rod igniting the pellets properly? I suspect it is.
b. Is the auger feeding pellets properly into the burn pot?
c. Does it look like the variable speed fan is supplying the right amount of air for combustion?
5. If it still looks OK, try closing the lid and observe the RTD thermocouple reading. The temperature should overshoot the set point by some amount, but it should not go wild. You can minimize the overshoot by starting off at less than 225F and then bumping the setpoint upward. I generally start my IW885 at 225F, but if I am planning on cooking at a higher temperature, I bump the setpoint in 50 degree increments until I get to the desired cook temperature. That minimizes overshooting.
6. I do not recommend trying to reinstall the heat shield and drip trays while the grill is burning. Thus, if you can get the temperature to stabilize at 225F, initiate the shutdown sequence and then observe what happens in the burn pot. No more pellets should be added, but the fan should continue to provide air for combustion until most of the pellets in the pot are consumed.