Vertical Smoker Temps

[Torquin]

My PBV4PS2 never gets to the "set" temp. If I set to to 250, it will get to maybe 230, then drop off to 220 or around that. It's like the smoker just can't keep up. I know that is can, though, because if I set it to much higher, the max of the control, it will go ahead and heat up. This doesn't make sense to me. If I set it to 230, I expect it to heat to 230 before it backs off and maintains the temp. I have attached a screen shot of the temp history.
Note: P1 (blue line) is just sitting on the same shelf as what I am cooking. P2 (green line) is submerged in the water tray. The spike in the gray line, the "set temp", is when I set it at 420 to get the smoker to heat up. You can see it began to heat up then (orange line), but when I put the temp back down to 230, the actual temp dropped to 30+ degrees below that.
The spike up in the green line is how I know my water was gone from the pan, and the spike down of the same line is when I refilled with water.
I monitor the meat temps with a separate thermometer setup.

Does anyone have any ideas about what's wrong here? It's like the control gives up when it gets within 30-40 degrees of the goal. You can see by the "grill temp" (orange line) and the P1 probe (blue line), the temps are close, so the temperature gauge in the controller is displaying the correct temp, but the controller is not telling the smoker to heat it up the set temp as it should. It does seem like a software issue to me.


Thanks,
Chris

 

[sparkyv]

How close are you measuring temps w.r.t. the controller T/C? Temps vary significantly from one measurement location to another.

Once I figured out where the hot (and cool) spots were on my grill, I just focus mostly on the internal meat temp.

 

[Torquin]

How close are you measuring temps w.r.t. the controller T/C? Temps vary significantly from one measurement location to another.

Once I figured out where the hot (and cool) spots were on my grill, I just focus mostly on the internal meat temp.

As I said, the temps the controller states and Probe 1 states, are very close. This can be seen on the cook history in my original post. In this case, I had probe 1 on the second shelf from the top, very near the controller probe.
To me, the fact that both of these read close to the same temp suggests that the controller logic is not figuring out that the temp is nowhere near the same as the "set temp" and therefore not triggering the auger to add more pellets.
It's curious though, that later, when I bumped the temp up to 300, it did seem to try to get the temp up close to that. I have not yet tried each temp to see how close it gets to the set temp.

Thanks,
Chris

 

[sparkyv]

Got it; thanks for the clarification.

In this case, I had probe 1 on the second shelf from the top, very near the controller probe.

Next question: what is the ambient temperature and the "P setting"?

 

[Steve In Pa]

My PBV4PS2 never gets to the "set" temp. If I set to to 250, it will get to maybe 230, then drop off to 220 or around that. It's like the smoker just can't keep up. I know that is can, though, because if I set it to much higher, the max of the control, it will go ahead and heat up. This doesn't make sense to me. If I set it to 230, I expect it to heat to 230 before it backs off and maintains the temp. I have attached a screen shot of the temp history.
Note: P1 (blue line) is just sitting on the same shelf as what I am cooking. P2 (green line) is submerged in the water tray. The spike in the gray line, the "set temp", is when I set it at 420 to get the smoker to heat up. You can see it began to heat up then (orange line), but when I put the temp back down to 230, the actual temp dropped to 30+ degrees below that.
The spike up in the green line is how I know my water was gone from the pan, and the spike down of the same line is when I refilled with water.
I monitor the meat temps with a separate thermometer setup.

View attachment 10322
Does anyone have any ideas about what's wrong here? It's like the control gives up when it gets within 30-40 degrees of the goal. You can see by the "grill temp" (orange line) and the P1 probe (blue line), the temps are close, so the temperature gauge in the controller is displaying the correct temp, but the controller is not telling the smoker to heat it up the set temp as it should. It does seem like a software issue to me.


Thanks,
Chris

Similar here for that model. This coming up after I recently updated the software. I have only done a couple cooks since the update, so I’m keeping an eye on things to see what my new “normal” is. Then I’ll go from there.

 

[Torquin]

Got it; thanks for the clarification.



Next question: what is the ambient temperature and the "P setting"?

Ambient temp was around 48, and the P setting, well, I'm not sure what you mean. If you mean the probe setting, I did not set any temp for the probes. I only use them to monitor internal temp and water temp, since I don't trust the controller temp.
I will say that i experience the same thing if the ambient temp is 70 or 80, also.
Thanks,
Chris

 

[sparkyv]

Some PB models have a P setting to adjust the temp response sensitivity via the auger feed rate.

 

[Torquin]

I ran a test yesterday and took screen shots from the app as I heated to various temps, changing the temp at the time of each screen shot, to the next higher temp. The chimney cap was at its lowest level for the entire test. There was no food in the smoker. The time between temp changes was at least 10 minutes, but in many cases, 15 minutes or longer.

Thanks,
Chris

 

[Freedbyjc]

My PBV4PS2 never gets to the "set" temp. If I set to to 250, it will get to maybe 230, then drop off to 220 or around that. It's like the smoker just can't keep up. I know that is can, though, because if I set it to much higher, the max of the control, it will go ahead and heat up. This doesn't make sense to me. If I set it to 230, I expect it to heat to 230 before it backs off and maintains the temp. I have attached a screen shot of the temp history.
Note: P1 (blue line) is just sitting on the same shelf as what I am cooking. P2 (green line) is submerged in the water tray. The spike in the gray line, the "set temp", is when I set it at 420 to get the smoker to heat up. You can see it began to heat up then (orange line), but when I put the temp back down to 230, the actual temp dropped to 30+ degrees below that.
The spike up in the green line is how I know my water was gone from the pan, and the spike down of the same line is when I refilled with water.
I monitor the meat temps with a separate thermometer setup.

View attachment 10322
Does anyone have any ideas about what's wrong here? It's like the control gives up when it gets within 30-40 degrees of the goal. You can see by the "grill temp" (orange line) and the P1 probe (blue line), the temps are close, so the temperature gauge in the controller is displaying the correct temp, but the controller is not telling the smoker to heat it up the set temp as it should. It does seem like a software issue to me.


Thanks,
Chris

Absolutely normal for all vertical pellet smokers…



Unless your oven thermometers or meat probes, specifically not meant for measuring grate temperatures, were positioned like this (see photo … OK, yes …it’s different on your vertical but you get the jist) on the digital temperature probe in your cabinet the temperature reading comparisons are totally invalid for comparison to the “Actual” temperature shown on the controller. Your grate temperatures are never going to match the actual temperature shown on the controller.



Yes, It’s horizontal in the photo but hopefully, you get the point.



The PitBoss controllers algorithms are set to create a temperature environment throughout the cabinet... not that exact temperature readings at every point across the grates.



If you’re interested in the grate temperatures, you’ll have to get a secondary probe specifically designed to measure that. Usually they have squared off or blunted tips and always come with grate clips.



The digital temperature showing on the controller is the temperature probe mounted on the back side of the cabinets that height ... it’s not “the grill” or “grate” temperatures. Your grate and lid probes are going to be different and probably higher or lower due to their placement in the cabinet .



Watch your digital, as it controls the controller, and keep an eye on your grate temperature but the IT on your meat probe is the one that’s the most important.



The “probe problem” is that folks don’t know enough about their PitBoss smokers design to know that the digital temperature shown on the controller and the grate temperatures are almost never going to match.



Remember, your PitBoss has a controller with an awesome algorithm that runs the smoker. After you’ve used it a few times you’ll realize that it works and works well. Relax... put your temperature probes in the food where they belong and let that awesome smoker you bought do the work for you. Smoke On!

 

[GeekChef]

My PBV4PS2 never gets to the "set" temp. If I set to to 250, it will get to maybe 230, then drop off to 220 or around that. It's like the smoker just can't keep up. I know that is can, though, because if I set it to much higher, the max of the control, it will go ahead and heat up. This doesn't make sense to me. If I set it to 230, I expect it to heat to 230 before it backs off and maintains the temp. I have attached a screen shot of the temp history.
Note: P1 (blue line) is just sitting on the same shelf as what I am cooking. P2 (green line) is submerged in the water tray. The spike in the gray line, the "set temp", is when I set it at 420 to get the smoker to heat up. You can see it began to heat up then (orange line), but when I put the temp back down to 230, the actual temp dropped to 30+ degrees below that.
The spike up in the green line is how I know my water was gone from the pan, and the spike down of the same line is when I refilled with water.
I monitor the meat temps with a separate thermometer setup.

View attachment 10322
Does anyone have any ideas about what's wrong here? It's like the control gives up when it gets within 30-40 degrees of the goal. You can see by the "grill temp" (orange line) and the P1 probe (blue line), the temps are close, so the temperature gauge in the controller is displaying the correct temp, but the controller is not telling the smoker to heat it up the set temp as it should. It does seem like a software issue to me.


Thanks,
Chris

The PBV4 controller is WAY too dampened! The PID is so laggy and non responsive to changes…..as it approaches the setpoint, the gain is so low that it won’t reach setpoint. The only way I got it to reach at low temperatures was to set up the temperature to +20 degs and hold the Prime button when it stalled to get more pellets to fuel up the flame. And it sort of worked…..but I got tired of that and installed a spare ReqTeq controller and all those issues went away. I love my smoker, but that controller needs a lot of help!

There are several posts of my upgrade….here is one.
https://www.pitbossforum.com/threads/pbv4ps2-controller-upgrade-options.1099/post-6593

 

[sparkyv]

Any way to tune that PID controller on the PB?

I don't seem to have this issue severely enough for it to be a concern on my Lexington.

 

[GeekChef]

Any way to tune that PID controller on the PB?

I don't seem to have this issue severely enough for it to be a concern on my Lexington.

U fortunately no. No hidden menus that I am aware of, but that would be great! Would have to buy a PID controller from another company.

 

[Torquin]

I cannot imagine an algorithm that says to take the temp reading, disregard it, and never match the setting I put in place. That makes no sense, and Pit Boss wouldn't have a business if that's how it worked, because no one wants a controller that does not do what they tell it to do. If there were some kind of "necessary, magic algorithm" to make things good in the smoker/grill, then that would take place behind the scenes and the controller would tell me that my temp matches what I set it to and I would not be the wiser, unless I added additional thermometers.
But, as I have mentioned in previous posts, I set the smoker to go to one temp, and it never gets there. I believe that my controller temp probe is correct since measuring with one of the meat probes gives close to the same reading. The temp probe reading does not make up for the fact that the controller temp setting is never reached, or even close.

Thanks,
Chris

 

[GeekChef]

The proportional part of the PID algorithms work by taking the error between the setpoint and measurement and multipling it against a gain(P). If the gain is not large enough the the system will be very laggy….very slow to respond…and…if the gain is very low then the smoker has an impossible task of reaching setpoint at very low temperatures. Low gain means no overshoot but slow response. Who ever programmed this for pit boss(because it wasn’t them) put a ton of filtering around the measurement as well so the displayed measurement doesn’t catch up to the real measurement and they like it that way. It makes you not get angry when the display is erratic.

I understand why you might not believe all the above but I as a test I connected my ReqTeq controller to my pitboss and I let the ReqTeq control and let the pitboss monitor and vice versa…..and the reqTeq controller gain is Way more aggressive….the PB4 that I have gets to temp and stays at temp very quickly by overshooting a bit with the Reqteq but not with the Pitboss controller.

I love my pitboss and wish they would allow us to adjust the gain higher as that would fix this issue….but they won’t. Even putting an Amazon PId controller on there would be better in my opinion.

 

[Torquin]

The proportional part of the PID algorithms work by taking the error between the setpoint and measurement and multipling it against a gain(P). If the gain is not large enough the the system will be very laggy….very slow to respond…and…if the gain is very low then the smoker has an impossible task of reaching setpoint at very low temperatures. Low gain means no overshoot but slow response. Who ever programmed this for pit boss(because it wasn’t them) put a ton of filtering around the measurement as well so the displayed measurement doesn’t catch up to the real measurement and they like it that way. It makes you not get angry when the display is erratic.

I understand why you might not believe all the above but I as a test I connected my ReqTeq controller to my pitboss and I let the ReqTeq control and let the pitboss monitor and vice versa…..and the reqTeq controller gain is Way more aggressive….the PB4 that I have gets to temp and stays at temp very quickly by overshooting a bit with the Reqteq but not with the Pitboss controller.

I love my pitboss and wish they would allow us to adjust the gain higher as that would fix this issue….but they won’t. Even putting an Amazon PId controller on there would be better in my opinion.

I agree. I just want it to get the temp within 5 degrees of what I set and keep it there. Seems like a very simple request, just like for your oven in the house.

Chris