Help! Tunneling? Controller? Other?

[TheGrumpyGriller]

Here's the background...

• Last week I had ribs, chicken, burgers, and a butt on the Timberline 1300 - it was set at 225 and was running fine for about 6 hours and then the temp toke a nosedive. It appears the fire went out, though I managed to do a restart - grill was thoroughly cleaned afterwards.
• On Saturday, I had some homemade bacon to smoke, so I threw a piece on at 165. No issues for 3+ hours, then same thing - temp nosedive. When I took the racks out the firepot was overflowing significantly with pellets. After this I spent almost three (3) hours on with Traeger support, including doing a video stream. Their conclusion was either a tunneling issue, or the controller. Understandably, they wanted to explore all options before sending out a new controller. Since they weren't able to really have me do anything to identify the cause, they are sending me a new one.
• On Sunday (actually 11 PM on Saturday) I decided to take a big risk and start a full packer brisket I had already prepped and had sitting in the fridge. The Traeger was set to 165 and it was perfect for about 14 hours....around the 15 hour mark, I saw the temp starting to decrease quickly (10-20 degrees in 5 minutes maybe), and I know that the pellet hopper was fully and flat (so no tunneling). I ended up doing another restart (though I am not positive I needed to), so....

Any thoughts on whether the controller is the real issue, or did I overreact on the temp drop with the brisket?

Thanks!

 

[traeger860]

It it's not the controller, it might be the hot rod. Any chance the pellets are bad/wet?

The 10-20 degree swing over 5 minutes wouldn't concern me if it started to climb back up on it's own after that. Did you ever notice a 10-20 degree swing in the opposite direction?

 

[TheGrumpyGriller]

It it's not the controller, it might be the hot rod. Any chance the pellets are bad/wet?

The 10-20 degree swing over 5 minutes wouldn't concern me if it started to climb back up on it's own after that. Did you ever notice a 10-20 degree swing in the opposite direction?

On the last cook, I did see the swing upwards as well after I restarted the grill.

 

[JamesB]

On the last cook, I did see the swing upwards as well after I restarted the grill.

If you restarted the grill before a normal shutdown, without cleaning out the fire pot, I would definitely expect to see a temp surge as the excess pellets are burned.

 

[RemE]

I've had only 1 flame out in 7+ years of Traeger use. My newer Timberline 850 lost fire shortly after I had the hood open while I wrapped the meat.

A couple of points, with the hood open the older grills cranked up the heat. The newer grills seem to detect this and are not supposed to over react.

Hot rods are only active when lighting the grill, once running, the controller manages the fire so it's either loss of fuel from a tunnel, bad pellets etc. or bad controller, jammed auger, bad fan or blocked air passages.

It's really unusual to lose fire when just cruising on a long cook. One thing we have discussed is power glitch possibility overnight, which could trigger a shutdown. Some of us now use a small UPS backup just to be safe on long cooks.

Also, if using a Fireboard, setting a low temp alarm on the pit temp to let you know should something go wrong in the night.

Lastly, I have seen some unusual temperature fluctuations on long low cooks that I can't fully explain. My last brisket cook had large swings in the beginning, then a lower than normal period, then back to normal. I thought perhaps my smoke tube caused it but don't know for sure. I made an automatic pellet stir mod so tunneling is not a factor. The grill was deep cleaned before the start, used 100% Hickory.

Here's the plot of that cook, bottom line, these aren't perfect systems;

 

[TheGrumpyGriller]

I am using Pit Boss pellets and have never had any issue - with it going perfectly fine for 16 hours, it's possible I may have overreacted when I saw the temp taking a nose dive and didn't want to lose my expensive brisket

On this last cook, tunneling was definitely not the issue as I keep the hopper full and flattened it out every once in a while, never going below 65%. I'll clean everything again and clear/re-prime the auger just in case. Perhaps I'll also completely empty the hopper and make sure there's no obvious moisture.

Traeger is sending a controller, but maybe I'll see how things go next couple of cooks before I make that switch.