Pro Series 820 Internal Temperature Sensor Issues

Jsemark

New member
Joined
May 22, 2020
Messages
7
Reaction score
1
Points
3
Location
Fountain Inn, SC
First post, but I've read many threads on this site. Thanks for the opportunity to participate here! This is my third smoker, first pellet smoker. Picked it up from Lowe's a week ago and was excited to fire it up. Impressed with the build quality, all felt solid, nothing felt cheap. But......

I've used the smoker 4 times now. The "actual temperature" noted at the panel (from the mounted internal temperature probe) reads consistently higher than the actual temperature. I have taken the Pit Boss provided meat probe and a separate wireless digital probe and located them each within an inch of this mounted sensor for the burner. The Pit Boss internal meat probe and my separate wireless probe measure within 15 degrees of each other.

The following is a typical snap shot of the temps I've had (also see attached picture):

Grill set at 350 deg F
"Actual" Temp read 410 deg F
PB Meat Probe read 303 deg F
Dial in Grill Lid read 320 deg F
External wireless probe located at the "Actual" Temp probe read 288 deg F

These temps were taken with the grille set point unchanged for 20 minutes, no food on the grille, and the lid closed the entire time. At no time has the "actual" temp displayed on the controller been anywhere near the the Pit Boss provided meat probe, with the probe within an inch of the "actual" sensor on the left side of the grille. When the grille is set at 300 to 350 deg, the difference is always over 100 deg F, but of course it's closer when smoking, about a 30 deg F differential.

The first time I used the grille, I trusted the "actual" temp to be correct and after an hour beyond the recommended cook time, food was still far from done, so I increased the temperature and the chicken breasts ended up dry. The second time, I tested the grille with no food in it for over an hour (results noted above) and then cooked a pork tenderloin with the cook time within the expected range, but only because I based the settings on what the meat probe told me for temp. I grilled some fillet steaks that turned out great, but I set the grille at 500 deg F, but based on the meat probe sensor, as grilling below 400 deg F. Tasted great but the sear was minimal. Also smoked an 8 pound Boston butt for twelve hours, 6 set at 250 deg F and 6 set at 350 deg F and still only reached an internal final temp of 192 deg F. Some of the butt was great, but thicker parts were not quite pulled pork tender. I'm second guessing everything, because I can't trust the temps.

I went to Pit Boss' website and filed a case 5 days ago. No reply at all, but I did start getting emails trying to sell me accessories. I either need a new temperature probe or controller calibration, if that's possible. Any suggestions? Anyone had similar issues?
 

Attachments

DaveXDm9

Moderator
Staff member
Joined
May 11, 2020
Messages
524
Reaction score
176
Points
43
Location
Tennessee
I do know the meat probes are horrible on the Pro Series and the accuracy is not even close. What change for me was I now use my PS 1100 in my garage as I open the door and it is right at the edge and keeps the majority of the smoke out. Once i did that my temps are now 5 - 10 off from the controller and the temp on the lid. To me this grill is very picky when it comes to weather and specifically wind or a breeze throws it off. By the way opening a case with PB is painful experience and honestly I think they only look at them when they feel like it. Use facebook or call them that is the only way you are going to get anywhere with them. I decided that I am going to buy a Rec-Tec controller w/ WIFI and replace it on the PS1100 and see if a PID controller will allow me to use outside.
 

DaveXDm9

Moderator
Staff member
Joined
May 11, 2020
Messages
524
Reaction score
176
Points
43
Location
Tennessee
Interesting note I remove the grill lid temperature gauge and tested it on boiling water. The highest temp it hit was 150 so I adjusted the gauge by using pliers by turning the probe counter clockwise as I believe this is how you calibrate these types and now it is reaching 210.
 
  • Thread Starter Thread Starter
  • #4

Jsemark

New member
Joined
May 22, 2020
Messages
7
Reaction score
1
Points
3
Location
Fountain Inn, SC
Dave, thanks for your input and taking the time to check your temps. I check my temperature probes using boiling water as well. Results...

Lid dial was 200 deg F. Not a critical gauge, but worth checking. My gauge has no set screw or anything that appears adjustable.
Pit Boss meat probe measured 216 deg F.
My wireless digital probe (2 probes) measured 213 deg F and 214 deg F
I have two ThermoPen type hand held probes. They both measured 212 deg F

The only thing I couldn't directly measure was the actual Pit Boss grill probe that controls the grill temperature, due to the wire length from the control board. I removed the probe's protector plate and laid the Pit Boss meat probe along side it within 1/4" with the tip ending at the same point. Closed the lid and let it settle at 450 deg F. With the grill reporting an "actual" temperature of 450 deg F, the meat probe was reading 340 deg F.

Conclusion is either the grill probe or the controller is bad. It's been 7 days and no reply on the case opened on the Pit Boss web site. I will give try to call them on Tuesday after the holiday.
 
  • Thread Starter Thread Starter
  • #5

Jsemark

New member
Joined
May 22, 2020
Messages
7
Reaction score
1
Points
3
Location
Fountain Inn, SC
Busy week, finally got around to calling Pit Boss today. The message gave an option of holding or having them call back. Working in the office, so I just left it in the background for an hour and a half, then the line went dead. Called back and left my number and they called a few hours later.

They said control boards and sensors are the most common warranty replacements, no issue. Will send a replacement for each. Their parts are backed up, so they expect them to ship end of June.
 
  • Thread Starter Thread Starter
  • #6

Jsemark

New member
Joined
May 22, 2020
Messages
7
Reaction score
1
Points
3
Location
Fountain Inn, SC
Thanks Carl,

I received a replacement controller and temperature probe from Pit Boss and installed those. I tested the new controls in boiling water. The Pit Boss meat probes indicated on the control screen that the boiling water was at 209 deg F. With the grille probe sitting in boiling water, the grill controller indicated 235 deg F. As you increase temperature, the discrepancy increases quickly. If I increase the setting until the grille thinks its at 425 deg F, the meat probe mounted in the same place measures 300 deg F. So, really the results with the replacement controller and probe are within a few degrees of what I got with the original controller and probe.

Not sure where else to go with this. I really regret the decision to purchase this grille, as it's very difficult to control temperature with the accuracy. I can't get the grille hot enough to sear steaks well, since it thinks it's much hotter than it really is. If there was a third party controller and/or probe, I may would give that a try, but I don't see a drop in replacement anywhere online.
 

DaveXDm9

Moderator
Staff member
Joined
May 11, 2020
Messages
524
Reaction score
176
Points
43
Location
Tennessee
The meat probes I would not trust it at all. Pellet grills are going to swing in temp it does not matter how much you pay for a grill they will swing. PID controllers temps swing as well not as much as a Non-PID,but they do.

try doing this start your grill based on the manual as you know set to smoke and start it up. Once the smokes clear from the grill then close the lid. Now do not increase the temp yet wait 6-7 minutes then set the grill to the desire temp.

Once you have set it to the desire temp let the grill run for 15 - 20 minutes prior to adding food to the grill. This will help stabilize your temp and let me know if that works and keep temps normal. It will siwng by +10/-10 maybe but it is not going to hurt the food you are cooking.
 
  • Thread Starter Thread Starter
  • #8

Jsemark

New member
Joined
May 22, 2020
Messages
7
Reaction score
1
Points
3
Location
Fountain Inn, SC
Dave,

I appreciate your input, but that's not what's happening here. I've done everything you recommend above. When the grille adds pellets to increase the temperature, the grille temp increases 50 to 100 deg F, then the temperature drops again fairly quickly after that cycle. That's not my real concern. The concern is at no time does the grille temp read consistently with any other probe I have.

To troubleshoot, I removed the grille probe and placed it in a pot of boiling water. In that same pot, I placed the two meat probes plugged into the grille's controller, my digital thermometer with two probes, and two Thermopins. Left them there for twenty minutes with the water boiling on a separate gas burner to give the temperatures probes plenty of time to settle out. The probe controlling the grille read 235 deg. All six of the other probes, including the ones meat probes with the grille, all read between 207 and 212 degrees. Reinstalled the grille probe in the grille and place both meat probes and two wireless probes within an inch of the grille's probe. Increase temperature to 500 degs, and all probes read within 5 degrees of each other, except the grille probe, which reads 100 degs higher than all the others. The difference appears to increase linearly with temperature.

I did the same thing with the original controller and temperature sensor and got temperatures about 5-7 deg different (worse) than the replacements I got from Pit Boss. Boiling water should give a predictable result, and does, with the exception of the grille probe. My neighbor has the exact same grille and never has had this issue.

I don't know anything about PID controllers used by pellet grilles, but in an industrial setting, a PID controller (proportional-integral-derivative) improves control by allowing the controller to not only control to set point with a dead band ("x" deg F below setpoint = add heat, "x" deg F above setpoint =stop adding heating), but also looks at the rate of change between the temperature set pointand the set point. This allows the controller to know "I'm approaching set point rapidly, slow down the rate of heat increase" so doesn't overshoot set point as much. A PID loop can greatly help stability, if the gain constants are properly set, but any control system will of course always have fluctuation. Industrial controls are tuned during startup to real world conditions, but very likely any of these constants would be hard programmed for a small controller like this at the factory.
 

DaveXDm9

Moderator
Staff member
Joined
May 11, 2020
Messages
524
Reaction score
176
Points
43
Location
Tennessee
Dave,

I appreciate your input, but that's not what's happening here. I've done everything you recommend above. When the grille adds pellets to increase the temperature, the grille temp increases 50 to 100 deg F, then the temperature drops again fairly quickly after that cycle. That's not my real concern. The concern is at no time does the grille temp read consistently with any other probe I have.

To troubleshoot, I removed the grille probe and placed it in a pot of boiling water. In that same pot, I placed the two meat probes plugged into the grille's controller, my digital thermometer with two probes, and two Thermopins. Left them there for twenty minutes with the water boiling on a separate gas burner to give the temperatures probes plenty of time to settle out. The probe controlling the grille read 235 deg. All six of the other probes, including the ones meat probes with the grille, all read between 207 and 212 degrees. Reinstalled the grille probe in the grille and place both meat probes and two wireless probes within an inch of the grille's probe. Increase temperature to 500 degs, and all probes read within 5 degrees of each other, except the grille probe, which reads 100 degs higher than all the others. The difference appears to increase linearly with temperature.

I did the same thing with the original controller and temperature sensor and got temperatures about 5-7 deg different (worse) than the replacements I got from Pit Boss. Boiling water should give a predictable result, and does, with the exception of the grille probe. My neighbor has the exact same grille and never has had this issue.

I don't know anything about PID controllers used by pellet grilles, but in an industrial setting, a PID controller (proportional-integral-derivative) improves control by allowing the controller to not only control to set point with a dead band ("x" deg F below setpoint = add heat, "x" deg F above setpoint =stop adding heating), but also looks at the rate of change between the temperature set pointand the set point. This allows the controller to know "I'm approaching set point rapidly, slow down the rate of heat increase" so doesn't overshoot set point as much. A PID loop can greatly help stability, if the gain constants are properly set, but any control system will of course always have fluctuation. Industrial controls are tuned during startup to real world conditions, but very likely any of these constants would be hard programmed for a small controller like this at the factory.

I assume the controller that was sent to you is bad so I would reach out to PB and have them keep sending you controllers until one works.
 

Trkboss820

New member
Joined
Sep 14, 2020
Messages
1
Reaction score
0
Points
1
Location
San Antonio
Dave,

I appreciate your input, but that's not what's happening here. I've done everything you recommend above. When the grille adds pellets to increase the temperature, the grille temp increases 50 to 100 deg F, then the temperature drops again fairly quickly after that cycle. That's not my real concern. The concern is at no time does the grille temp read consistently with any other probe I have.

To troubleshoot, I removed the grille probe and placed it in a pot of boiling water. In that same pot, I placed the two meat probes plugged into the grille's controller, my digital thermometer with two probes, and two Thermopins. Left them there for twenty minutes with the water boiling on a separate gas burner to give the temperatures probes plenty of time to settle out. The probe controlling the grille read 235 deg. All six of the other probes, including the ones meat probes with the grille, all read between 207 and 212 degrees. Reinstalled the grille probe in the grille and place both meat probes and two wireless probes within an inch of the grille's probe. Increase temperature to 500 degs, and all probes read within 5 degrees of each other, except the grille probe, which reads 100 degs higher than all the others. The difference appears to increase linearly with temperature.

I did the same thing with the original controller and temperature sensor and got temperatures about 5-7 deg different (worse) than the replacements I got from Pit Boss. Boiling water should give a predictable result, and does, with the exception of the grille probe. My neighbor has the exact same grille and never has had this issue.

I don't know anything about PID controllers used by pellet grilles, but in an industrial setting, a PID controller (proportional-integral-derivative) improves control by allowing the controller to not only control to set point with a dead band ("x" deg F below setpoint = add heat, "x" deg F above setpoint =stop adding heating), but also looks at the rate of change between the temperature set pointand the set point. This allows the controller to know "I'm approaching set point rapidly, slow down the rate of heat increase" so doesn't overshoot set point as much. A PID loop can greatly help stability, if the gain constants are properly set, but any control system will of course always have fluctuation. Industrial controls are tuned during startup to real world conditions, but very likely any of these constants would be hard programmed for a small controller like this at the factory.
Hey jsemark,
I got the pit boss 820 a couple months back and I'm having the same issues. The digital temp ranges anywhere from 50 to 100 degrees higher than the actual temp. I have an accurate thermometer with 6 probes and have checked various spots in the grill to compare against the rtd probe and the lid thermometer. I checked all my probes in boiling water and all measured 212. I even checked the rtd probe in boiling water along with a after market replacement rtd probe. Funny thing is that the pit boss rtd prob and the replacement probe both stayed at 210 degrees in the boiling water. I have concluded a few things from this. I took one of my probes and lined it up almost exactly where the rtd probe is. Both my probe and the rtd digital temp rose very fast with close readings. However once over 350-400 degrees the rtd probe tends to get stuck at the higher temp as where my probe showed the temp drop on the down swing. So first off the area where the rtd probe is located is the hottest part of the smoker and you can feel high direct heat hitting this area pretty hard. This was proven by my wireless probe as well. Then as stated the second issue is that the pitboss rtd probe tends to get stuck at higher heat and stays about 50+ degrees hotter than my other probes. Not sure if this is due to the controller calibration or the probe itself. I found out the the lid temp is actually more accurate than the digital but the pitboss does a pretty good job at maintaining a consistent temp. I tried created a shield with aluminum foil to block some of the direct heat on the rtd probe but that didnt help. Long story short you just have to learn the smoker and to me the digital temp is useless. I just go off my probes in various locations and the lid temp to make sure im in range. A little disappointed on my end.
 

Latest Discussions

Top