Stampede Temperature control issues

[SpikeMike]

We have had our RT-590 for 3-1/2 years. We use it all the time. Probably average about two times per week. Smoked a lot of brisket, pork butts, turkeys, chicken, …. This thing has always been consistent.

Until recently. I’ve had a couple things come out a little off. These are recipes I’ve used several times. Yesterday cooked wings and the temperature on the grill fluctuated quite a bit. It never showed actually the set temperature of 400. But, I suspected that the temperature was actually at or above 400.

So, today I used a Thermapro probe to run a test. The Thermapro is not a meat probe. It is a grill probe. It has a little stand to keep the probe up off of the grates.

Started the grill and set it at 350. The grill started up and showed the temperature going up consistently until it hit 319. At this point, it actually showed falling a little to 314. After a little bit, the temperature started going up again to 350 where it stayed.

The Thermapro showed very similar until the grill showed as stopping at 319. The Thermapro showed a continuous climb all the way up a little past 400 and held steady there.

So, below the 319 glitch, the grill and the Thermapro showed about the same. After the glitch at 319, the grill and the probe diverged by 50 degrees.

Called Recteq. They said that long pellets are causing the temperature fluctuation and that I need to trust the grill temperature reading, not the probe reading.

Based on this grill’s history, something has changed. Only recent cooks have had problems. And a 50 degree difference between probes shows that something is off.

Anyone have any suggestions?

 

[Jim6820]

Have you changed pellets recently? Changed anything else? What was the outside temperature and how does it compare to previous cooks? The devil is in the details.

 

[SpikeMike]

Yep. Details.
I'm using Pit Boss Competition Blend pellets. I've used these pellets for 90% of the time that I've had this grill. Could be a bad batch.
Right now its 101 degrees outside. I'm just outside of Houston.
Until recently, have not experienced any issues with outside temperature and the grill's capabilities.

 

[Lager1829]

Have you ever let the pellets run through, emptying the hopper and clean out the excess pellet dust?

 

[Nerdygrrl]

Yep. Details.
I'm using Pit Boss Competition Blend pellets. I've used these pellets for 90% of the time that I've had this grill. Could be a bad batch.
Right now its 101 degrees outside. I'm just outside of Houston.
Until recently, have not experienced any issues with outside temperature and the grill's capabilities.

The greatest trick the devil ever played was convincing people their pellets were to blame.

When you say until recently, how long ago did the problem start? Are you up to date on your firmware? When was the last time you cleaned your internal thermometer?

 

[SpikeMike]

Have you ever let the pellets run through, emptying the hopper and clean out the excess pellet dust?

Thank you for the suggestion. Yes. I do this regularly. Because I've been having issues, I cleaned it all out a few days ago.

 

[SpikeMike]

The greatest trick the devil ever played was convincing people their pellets were to blame.

When you say until recently, how long ago did the problem start? Are you up to date on your firmware? When was the last time you cleaned your internal thermometer?

This has been creeping in for the last month or two. I don't know about the firmware. I'll have to check that out. I don't think that I've ever really cleaned the RTD temp probe. Should I hit it with some cleaner and a scotch pad?

 

[pungo]

Are you up to date on your firmware?

AFAIK, on a 3.5 yr old RT, the firmware is locked at the version it shipped with

 

[Jim6820]

When was the last time you cleaned your internal thermometer?

This! Definitely clean the RTD temp probe; gently. A ScotchBrite pad and a little cleaner or soapy water followed by a wipe down with a wet and then dry paper towel should do it. The “gently” part is to avoid bending the probe. Do check to see that it hasn’t been accidentally bumped and bent over against the chamber wall.

 

[Nerdygrrl]

This has been creeping in for the last month or two. I don't know about the firmware. I'll have to check that out. I don't think that I've ever really cleaned the RTD temp probe. Should I hit it with some cleaner and a scotch pad?

If it's been going on that long it's hard to blame the pellets. It's got to be in house. So it's either the thermometer not registering or the controller not responding to the temp signal.

It's so weird that the two probes were in lock step and then diverted at 319.

AFAIK, on a 3.5 yr old RT, the firmware is locked at the version it shipped with

Ah ok. So that's one more thing to rule out

 

[Gonefishin]

Pacman had a blurb on updating the firmware from the app a few posts down in this thread. https://www.recteqforum.com/threads/latest-rt-590-firmware-version.5281/

 

[SpikeMike]

Just an update. I called Recteq. Went through the onboard diagnostics. The auger feed rate was off so we reset it to 30. I have never messed with any settings, so I don't know why it was off. Anyway, I was advised to start the grill, set it to 400, then leave it for an hour and see how it goes. Again, heating up went smoothly until the grill hit 385. My other probe was right in line with the grill until this point. At this point, the grill showed falling to 370 and stayed there for about five minutes. And, at this point, the other probe showed increasing temps constantly. After the five minutes or so, the grill showed increasing temp up to 400 where it held. But, by this time, the other probe showed 440 and held there. So the difference between the grill and the other probe was 40 degrees for the whole hour.
Recteq keeps telling me to trust the grill reading.

 

[DesertRat]

I'm from Recteq and I'm here to help. Wait a minute. That was...Never mind.
Just a suggestion. Get a 2nd probe device and see which it agrees with, or comes closest to agreeing with. 40 degrees is a lot to me.

 

[Nerdygrrl]

Just an update. I called Recteq. Went through the onboard diagnostics. The auger feed rate was off so we reset it to 30. I have never messed with any settings, so I don't know why it was off. Anyway, I was advised to start the grill, set it to 400, then leave it for an hour and see how it goes. Again, heating up went smoothly until the grill hit 385. My other probe was right in line with the grill until this point. At this point, the grill showed falling to 370 and stayed there for about five minutes. And, at this point, the other probe showed increasing temps constantly. After the five minutes or so, the grill showed increasing temp up to 400 where it held. But, by this time, the other probe showed 440 and held there. So the difference between the grill and the other probe was 40 degrees for the whole hour.
Recteq keeps telling me to trust the grill reading.

It's definitely not the feed rate. It can really be only two things: internal thermometer not reading accurately or the controller not getting the message correctly. Those are the only two components involved in this.

Did you clean the thermometer? If yes, verify with another probe.

 

[dthobbs]

Have you changed pellets recently? Changed anything else? What was the outside temperature and how does it compare to previous cooks? The devil is in the details.

I' tested mine the same way with the same results