# Pit-Boss 820D Temperature Control Using Factory Controller



## banjo (Jun 10, 2018)

*Factory Temperature Controller for 200, 225, 250, 300, 350 dF.
*
_Note: Themocouples are type K, and were calibrated against boiling water, adjusted for altitude, and are within 2 dF of that value.
Note: no meat on racks during these tests.
Note: Charts at bottom of this post.
Note: If anyone is interested in the raw data, let me know and I'll upload to my blog site. It's about 11 Meg.
Note:  I used Pit-Boss Pro Blend pellets for the test.
Note: These are small-mass thermocouples, so they will respond much quicker than the larger-mass RTDs located in the cooking chamber.  This will result in showing larger high and low temperature swings.  However, they are true temperature swings; the larger mass RTDs are slower to respond and thus dampen the depiction of  the temperature swings.  The major consideration should be the average, and how well it cycles around the temperature setting._



A month or so back, a friend and I each purchased this model smoker. We were both disappointed in the temperature controller that came with the unit.

I wanted to get a feel for what was going on, so I instrument ed the smoker with four (4) thermocouples, and two (2) relays.

The thermocouples (type K, using Max31855 thermocouple amplifiers) would monitor temperatures at the following locations:

Combustion Chamber
Location in center of grill where meat usually is place first; as more meat is added, it typically is added left and right of the center.
The current location where the Pit-Boss 820D has their RTD temperature sensor (left front of smoke chamber)
Outside air temperature
The two (2) 120vac relays were used to monitor (one each):

Auger motor
Fan motor
Using a Raspberry Pi 3 (RPi), I wrote a C++ program to monitor these different devices (six total), at a 1-second interval, and to store that on the RPi. I streamed this across the network so that I could monitor all six values while performing the tests. The total tests took around six (6) hours, so a lot of data at 1 second for 6 devices.

The test consisted of multiple segments, with each segment being associated with setpoint temperature s for 200, 225, 250, 300, 350 dF.  Each segment had a time interval of at least 15 minutes, and some went to 40 minutes (I was sometime occupied and didn't get to switch the setting at the same times).

Below are the charts of the temperature settings.


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## mike243 (Jun 10, 2018)

Lid temps match controler im at 1.5 hrs in and temps are very stable with p6 setting


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## mike243 (Jun 10, 2018)

Sorry on the double tap


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## banjo (Jun 10, 2018)

mike243 said:


> Sorry on the double tap





mike243 said:


> Lid temps match controler im at 1.5 hrs in and temps are very stable with p6 setting



Is that the model 820D?  It doesn't look like my factory controller at all.


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## mike243 (Jun 10, 2018)

Pit Boss Austin LX was wondering what yours looked like and if they were the same unit for both


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## mike243 (Jun 10, 2018)

My probe#2 is off and they are supposed to be sending me another 1 but I wanted to see what impact the bone had and how well the heat circulates in the unit,kind of hard when both probes don't match


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## banjo (Jun 10, 2018)

mike243 said:


> Pit Boss Austin LX was wondering what yours looked like and if they were the same unit for both



Mine doesn't look like that at all.  I don't have any way to compare the factory 820D controller with the one you have; they could even look identical but be running different software.  This is what mine looks like (picture from google search, as I've pulled mine out of the smoker and replaced it with a Savannah Stoker).
.
.


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## mike243 (Jun 10, 2018)

Reading the book it sez to use a pointy object to set P setting but no need it is a raised bump that is very easy to set with your finger so was very happy about that,the book cautioned about pushing too hard ect.love the 2 probe set up and i have other wifi temp gauges if needed but all are like me old and maybe off a little lol


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## banjo (Jun 18, 2018)

My thermocouple measurement rig.


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