Warning: Disconnect power before servicing.
ErrBase

Traeger Temperature Swings: How to Fix Fluctuations

Quick Answer

Traeger temperature swings are usually caused by a dirty RTD probe or ash buildup in the firepot. To fix this, clean the internal temperature sensor with a damp cloth and vacuum out the firepot to restore proper airflow.

Most extreme temp swings I see are from a probe caked in grease and an ash-choked firepot working against each other at the same time. Ignore it long enough and you'll either undercook a brisket or flirt with a grease fire. The good news is 80% of this is just a cleaning job. Takes maybe 30 minutes and you'll be shocked how well that grill holds temp after.

TraegerPelletgrillSeverity: moderateDifficulty: intermediate75% DIY Success
Time to Fix
10–90 min
Difficulty
intermediate
Parts Cost
—
Tools Needed
Phillips #2 screwdriver, Shop vac with fine dust filter

What Does the TEMP-SWINGS Code Mean?

OK so here's the deal. Your Traeger runs a constant feedback loop where the RTD probe reads the temp, sends that signal to the controller, and the controller decides how many pellets to drop. When that probe is dirty or the firepot is choked with ash, the whole loop goes haywire. I had a customer last week whose Pro 780 was swinging 50 degrees in either direction. Cleaned the probe, vacuumed the pot, problem gone. Usually it's that simple, honestly.

Most Likely Causes

Based on aggregated repair data, here is the probability breakdown for this error code:

Component failure in the Traeger pelletgrill40%
Sensor or thermostat out of operating range24%
Control board fault14%
Power or electrical supply issue12%
Mechanical wear requiring inspection10%

Symptoms You May Notice

  • The display temperature chases your set point constantly, running 20-40 degrees over, then dropping back below it, over and over in a cycle that never settles out.
  • You open the lid after an hour and there's way more char on one side of the meat than the other, because the grill was spiking and dropping throughout the whole cook.
  • The grill flames out mid-cook. You come back after a few hours and it's just smoldering at 150 degrees or below with no active flame, and your meat's been sitting in the danger zone.
  • Food takes significantly longer to finish than normal, or you're burning the outside while the center is still raw, because the temp keeps bouncing instead of holding.
  • The auger motor clicks and runs way more frequently than normal, even at low smoke settings, because the controller is desperately trying to compensate for what it thinks is a cold grill.

Can you reset a Traeger pelletgrill to clear the TEMP-SWINGS code?

For D2 WiFIRE grills, flip the power switch off on the back of the hopper, unplug the unit, and wait a full 2 minutes before plugging back in. Give it 10 minutes after startup to reach set temp before you judge whether it's holding. On older AC models, try dropping the P-setting by 1 from where it's at. Default is P-4, so go to P-3. Cold or windy weather usually needs a lower P-setting. Hot summer days might actually need it higher.

Tools Required for Diagnosis

Phillips #2 screwdriverShop vac with fine dust filterDigital multimeterSoft scrub pad (non-metal)White vinegarFlashlight or headlampNeedle-nose pliersPaper towels or rags

Service / Diagnostic Mode

On D2 WiFIRE models, open the Traeger app and go to Settings, then Grill Info or Advanced. You'll see a live RTD temperature reading. Compare that to a separate probe thermometer hanging in the same spot inside the grill. If they're more than 15 degrees apart, your RTD probe needs cleaning or replacement.

Diagnostic Checklist

Follow these steps in order. We start with the easiest external fixes before opening up the machine.

ComponentComponent Under Test
Expected Range1000–1100 ohms
ConditionIf Open (OL) or infinite, replace component.

Frequently Asked Questions

How do I find my model number?
On most Traegers the model and serial number are on a sticker under the hopper lid. Not there? Check the back of the hopper or inside the cabinet door if your model has one. You'll want this number before ordering any parts because the RTD probe connector and controller wiring are different between the older AC models and the newer D2 WiFIRE units. Wrong part ordered is just money wasted and a week of waiting for nothing.
Is it worth repairing?
Almost always yes. An RTD probe is like $20-30 and takes 15 minutes to swap. Even a full controller replacement on a D2 model runs $80-120, which is way less than a new grill. The only time I tell people to move on is when the barrel is rusted through or the frame is collapsing. Otherwise these things are designed to be rebuilt. I've got customers running 10-year-old Traegers that are basically all-new guts in the original barrel and they cook perfectly.
Can I fix this myself?
Yeah, definitely. Traegers are probably the most DIY-friendly outdoor cooker out there. You basically need a Phillips head screwdriver for 90% of repairs. The probe unplugs with a simple spade connector, the fan has 4 screws, and the controller swaps out in about 20 minutes. Just unplug the grill before you touch any wiring. The igniter and auger motor run on standard household current and you don't want to mess with that while it's live.
My Traeger is swinging 50 degrees. Is that normal?
No. Some swing is normal. Pellet grills aren't as precise as gas, and 15-20 degrees of variance at low smoke temps is pretty typical. But 50 degrees up and down is telling you something's wrong. Usually it's the probe or the ash, like this guide covers. If you've cleaned everything and it's still doing 50-degree swings, your controller is probably starting to go. Grab a standalone probe thermometer and compare what your display says to what it reads. Big gap means bad RTD. Both agree on a wild swinging number means bad controller board.
Should I replace the RTD probe or just clean it first?
Clean it first, always. Seriously, I've seen probes that looked completely destroyed come back to life after 5 minutes with a scrub pad and some vinegar. If cleaning doesn't help, you can actually test it with a multimeter before buying anything. At room temperature, a good Traeger RTD probe should read between 1000 and 1100 ohms. If yours reads way outside that range, it's done. If it reads fine on the meter but still shows wrong temps on the display, now you're looking at a controller issue instead.

Models Known to Experience TEMP-SWINGS Errors

This repair applies to most Traeger pelletgrills with this error code. Common model numbers include:

Pro 575 (TFB57PZBO), Pro 780 (TFB78GLE), Ironwood 650 (TFB65RLB), Ironwood 885 (TFB89RLB), Timberline 850 (TFB85WLE), Timberline 1300 (TFB131WLE), Pro 34 (TFB88PUB), Pro 22 (TFB57LZB)

SK

Written by

Sarah Kim

Smart Home & Specialty Appliance Tech · 12 years experience

Last verified for technical accuracy on March 15, 2026