Temperature Control Or Lack Of It

[J Walker]

I am posting my experience with my Lexington grill to see if my case is normal, and if so it may be good information to others. I believe I have resolved my control issue but I am not sure that all is normal. After I had a grease fire the temperature control was lacking. I called customer service and they reviewed my startup procedure and I was skipping the Smoke setting. They sent me a new temperature sensor. I installed the new sensor and the temperature control was worse than before. I found that I had to unplug the grill for several seconds and then plug it back in to clear the problem, perhaps like rebooting a computer. Then I use the initial Smoke setting until the dots at the bottom of the screen disappear (electric starter turns off). Then the grill temperature control is normal. If the startup is not normal the temperature can increase apparently without limit. Should I get another controller? Thanks

 

[Cowboy1955]

I am posting my experience with my Lexington grill to see if my case is normal, and if so it may be good information to others. I believe I have resolved my control issue but I am not sure that all is normal. After I had a grease fire the temperature control was lacking. I called customer service and they reviewed my startup procedure and I was skipping the Smoke setting. They sent me a new temperature sensor. I installed the new sensor and the temperature control was worse than before. I found that I had to unplug the grill for several seconds and then plug it back in to clear the problem, perhaps like rebooting a computer. Then I use the initial Smoke setting until the dots at the bottom of the screen disappear (electric starter turns off). Then the grill temperature control is normal. If the startup is not normal the temperature can increase apparently without limit. Should I get another controller? Thanks

I would cook on it 2-3 times and see what results you have. These grills are nothing more than a computer and you swap parts out sometimes it has to relearn everything from scratch
Just make sure and clean the temperature sensor after each cook
Hopefully this helps you

 

[J Walker]

I would cook on it 2-3 times and see what results you have. These grills are nothing more than a computer and you swap parts out sometimes it has to relearn everything from scratch
Just make sure and clean the temperature sensor after each cook
Hopefully this helps you

Thanks. I will use the grill while carefully following the proper startup procedure. I really hope after that the grill will not have the tendency to ramp up the temperature excessively if some part of the procedure is not followed. While installing a new temperature sensor, I found that removing the shield from the temperature sensor was not an easy task. Also, the shield did its job and the sensor was clean when I changed it. I can leave the shield off and clean the sensor easily and it will probably need it. My grill is a Lexington.

 

[Redoctapus]

Thanks. I will use the grill while carefully following the proper startup procedure. I really hope after that the grill will not have the tendency to ramp up the temperature excessively if some part of the procedure is not followed. While installing a new temperature sensor, I found that removing the shield from the temperature sensor was not an easy task. Also, the shield did its job and the sensor was clean when I changed it. I can leave the shield off and clean the sensor easily and it will probably need it. My grill is a Lexington.

I vacuum the ashes out of the crucible and bottom area of my PBV5 before each cook. My Masterbuilt Verticle and my GMG barrel type both advise filling the crucible 3/4ers full before reassembly. I don't recall this being mentioned in my PB MANUAL but PB has the prime button. I figure it's best to fill the crucible after each cleaning, it's my start up procedure.

Thanks. I will use the grill while carefully following the proper startup procedure. I really hope after that the grill will not have the tendency to ramp up the temperature excessively if some part of the procedure is not followed. While installing a new temperature sensor, I found that removing the shield from the temperature sensor was not an easy task. Also, the shield did its job and the sensor was clean when I changed it. I can leave the shield off and clean the sensor easily and it will probably need it. My grill is a Lexington.

I've been reading up on PID controllers installed in various pellet grills.
I do not see where there is internal memory storage from last cook.
The "learning" of a PID controller happens in and during the initial start up. Most start up procedures recommend a set point temp of 275 to 300F.
This is where the learning process is. The controller has a target, it starts feeding pellets at a known rate, it is monitoring the rate of increase (learning the btu's of the fuel) in temperature and how long it is taking to get there. As the calculations continue the loops are now knows that at a given feed rate the temp is rising X degrees per second(or minute) and compares this to the disparity to the set point temp aND actual. The computations are happening constantly. Through variable and or the algorithm the control will slow down the feed rate as the differential lowers until set point temp is reached. This minimizes temperature over shoot. Old controllers were just an on/off tape of feed/temp control, the auger feeds a set rate until set point is reached. When set point temp is reached the thermostat system stops auger feed, pellets continue to burn. When thermostat system senses a temp below set point temp it turns on the feeder, this cycle continues until pellets are all burnt up or unit is shut down.

With all that said I always, always fire up my smoker with the burn pot/crucible full and a set point of 275. My controller LEARNS the rates of fuel applied to temperature increase. So if one batch of pellets vary from the last pellets I used my PID controller just takes this in stride and seeks the set temp. Now it knows all the variables it needs to feed the fire and maintain a temperature.
I believe turning on the smoker and going to a low set point deprives the controller of needed data.
And I always step down temps about 20-25 degrees at a time especially in hot weather and the smoker is in the sun. So my unit goes into shut down mode a a very low temp.

 

[J Walker]

I have not gotten to the fine points of the rate of the pellet feed because I have been experiencing uncontrolled temperatures. I hope that strictly following the startup procedure in the operating manual for my Lexington will do the trick and my controller willoperat normally. According to the manual I must start in the Smoke setting which gives a temperature of about 180 degrees. There are dots at the bottom of the display that indicate the electric starter is on. I must wait until the dots disappear to raise the temperature setting. I might find that some of the steps can be skipped but I will establish a procedure that works reliable before shortening it. Thanks for the PID information. It could come in handy.

 

[Redoctapus]

I have not gotten to the fine points of the rate of the pellet feed because I have been experiencing uncontrolled temperatures. I hope that strictly following the startup procedure in the operating manual for my Lexington will do the trick and my controller willoperat normally. According to the manual I must start in the Smoke setting which gives a temperature of about 180 degrees. There are dots at the bottom of the display that indicate the electric starter is on. I must wait until the dots disappear to raise the temperature setting. I might find that some of the steps can be skipped but I will establish a procedure that works reliable before shortening it. Thanks for the PID information. It could come in handy.

When you have a few minutes, clean out the fire pot, add 1.5 cup of pellets. If your machine has a water pan fill it. If not put a half pan of H20 in the middle of oven. Turn on your smoker. Hit start, when you see smoke set temp to 250F. Sit back have beverage and see what happens. Note temp and time on paper at 15 minute intervals until reaches 250F. You should see a little over shoot. At this point you should be at full preheat and steady for 20 minutes. Then set your desired cook temp. Ya gotta start somewhere to trouble shoot ya need notes and procedure.