Temperature accuracy

[The smo king]

I’ve had my timberline for about a year. It functions well - starts, fires up, gets to temp, stays on temp consistently, probe seems accurate….but it seems to be 25-50 degrees cooler than what the controller says. I‘ve checked the ambient temperature in the cook chamber with a MEATER and with an oven thermometer. The MEATER and the oven thermometer have the same temp, within 5-10 degrees, while the controller is 40 degrees off. Controller says 300, other thermometers say 260. That’s the case even when they are setting right up next to the probe on the thermocouple. Traeger sent me a new thermocouple and after replacing, it’s the same.

anyone else have an issue like this? I can adjust temp and cook for doneness, but it makes baking with the Traeger a pain in the rump.

 

[Timmy]

Just about every member in the forum. Some members have issues the other way, hotter then set temp. I’ve had my Pro 780 since fathersday 2020. I bought a FireBoard thermometer and place an ambient probe right next to the Traeger probe. I set temp according to it. Ive baked several time doing it this way from cinnamon rolls to pizza.

Now you don’t have to spend big $ on the FireBoard, some members have been use the InkBird and other thermometers with good results.

 

[RayClem]

As @Timmy says, it seems to be a universal problem. With my IW885, the temperature is 5 degrees low at 225F, 25 degrees low at 325F, and 50 degrees low at 425F. Once I figured out the quirks of my smoker, I just set the controller at the proper setpoint to achieve the desired cook temperature. As long as you can measure the actual temperature, it does not matter what the controller says.

 

[Like Smoke]

My older model Texas doesn't have individual probes and I am happy about that considering all I read on this forum about their inaccuracy. Being a retired engineer that worked with ovens designed for sintering metals (1000 C and over), I had to deal with thermocouples, controllers and their accuracy. The things I read about temp deviation, leads me to believe that we are working with two problems. (1) A thermocouple (TC) can be calibrated to a very close degree of accuracy, but does Traeger use an accurate one. (2) If the readout controller is not matched to the TC there lays the problem. If the Traeger folks put together one of their products and grab a controller of of on shelf and a couple of TC's of another shelf without matching them, this could be one of the problems. Without having an electrical schematic of their controller I can't comment on how or if they adjust the differential between the two.

My Texas only has one thermocouple that is mounted inside on the controller end, and is only about 1/2 inch from the metal. It relies on the fan circulating the air towards both ends of the tank. I find this a strange place to measure heat that is cooking meat on the grill maybe 15 inches away. My controller readout is always about 30 degrees higher than my controller setting, but knowing this, I can still control my temps very close. My controller readout is always within 10 degrees of my analog thermometer mounted in the top of the lid about 5 inches from the smoke stack.

The other thing I have ran across is type of pellets I use. I have done some research and one thing that will vary my temp swings is the type of pellet I am using. Fruit wood pellets being a softer wood burn a little hotter than hardwood. Hardwood pellets might not burn quite as hot but do produce more smoke and ash.

I use an independent thermometer in the meat and have been pleased with the results.
I guess to close this I would follow RayClem's advice, figure out your smoker, measure the actual temperature and don't worry about the controller read out.

 

[RayClem]

My older model Texas doesn't have individual probes and I am happy about that considering all I read on this forum about their inaccuracy. Being a retired engineer that worked with ovens designed for sintering metals (1000 C and over), I had to deal with thermocouples, controllers and their accuracy. The things I read about temp deviation, leads me to believe that we are working with two problems. (1) A thermocouple (TC) can be calibrated to a very close degree of accuracy, but does Traeger use an accurate one. (2) If the readout controller is not matched to the TC there lays the problem. If the Traeger folks put together one of their products and grab a controller of of on shelf and a couple of TC's of another shelf without matching them, this could be one of the problems. Without having an electrical schematic of their controller I can't comment on how or if they adjust the differential between the two.

My Texas only has one thermocouple that is mounted inside on the controller end, and is only about 1/2 inch from the metal. It relies on the fan circulating the air towards both ends of the tank. I find this a strange place to measure heat that is cooking meat on the grill maybe 15 inches away. My controller readout is always about 30 degrees higher than my controller setting, but knowing this, I can still control my temps very close. My controller readout is always within 10 degrees of my analog thermometer mounted in the top of the lid about 5 inches from the smoke stack.

The other thing I have ran across is type of pellets I use. I have done some research and one thing that will vary my temp swings is the type of pellet I am using. Fruit wood pellets being a softer wood burn a little hotter than hardwood. Hardwood pellets might not burn quite as hot but do produce more smoke and ash.

I use an independent thermometer in the meat and have been pleased with the results.
I guess to close this I would follow RayClem's advice, figure out your smoker, measure the actual temperature and don't worry about the controller read out.

I guess Traeger figures that if the fire pot is covered by a flame shield and a large drip tray that the heat has to come up around the edges of the drip tray and circulate through the chamber. Thus, they put the thermocouple at the side of the chamber. However, as you say, the cooking is done some distance away from the thermocouple position. I like measuring the cook temperature close to the primary protein.

In one of Mad Scientist's videos, he was showing that in his very large offset smoker, the hottest area is on the top shelf nearest the smoke generator. Other spots in the smoker can be 50 degrees F or more cooler. The pit master can take advantages of such discrepancies by placing large pieces of protein in the hot spots and smaller pieces in cooler spots. Any Traeger with a smokestack is going to have temperature variations throughout the chamber. Even the newer models like my Ironwood that exhaust out the back slots will have some variation. Because heat rises, the top rack will always be hotter than the bottom rack, but the bottom rack might get more radiation from the hot drip tray. That is why you have to figure out exactly how your specific grill works.

 

[Keithes1]

Just got a pro 32 and found the grill temp around 45 degrees lower than the set temp. This will be an issue if it’s 45 low on 450 if I want to do pizza. I really don’t understand how they can be that far off. Pretty poor engineering in my opinion.

 

[RayClem]

Just got a pro 32 and found the grill temp around 45 degrees lower than the set temp. This will be an issue if it’s 45 low on 450 if I want to do pizza. I really don’t understand how they can be that far off. Pretty poor engineering in my opinion.

Yep. I have to set my Ironwood 885 to 450F to achieve an actual temp of 400F to cook pizza. On the Pro you will just have to set the controller to Max and hope for the best.

The grills measure temperature along the side of the cooking chamber. There will be temp variations from right to left, from back to front, and from top to bottom in the cooking chamber. Having these variations can be either bad or good depending upon what you are cooking .

 

[Tallyman89]

Has the probe been calibrated? Seems very simple. Just curious to see if it helps.

 

[RayClem]

While you can calibrate the internal meat probe, there is no way to calibrate the RTD temperature probe. Even if you could, the calibration would only be a one point- the freezing point of water which is so far from the 180-450F temperature range of the cooking chamber that it would be useless.

 

[Tallyman89]

Gotcha

 

[Slimpicker]

While you can calibrate the internal meat probe, there is no way to calibrate the RTD temperature probe. Even if you could, the calibration would only be a one point- the freezing point of water which is so far from the 180-450F temperature range of the cooking chamber that it would be useless.

Agreed, the RTD you see is what you get, the only thing to do is LEARN how far off your rig is, then adjust... this is why we ALL here suggest you buy a reliable 3rd party probe system to give you true pit temps and meat temps, this will save you more than you will ever spend on the extra probes.

 

[Tallyman89]

Agreed, the RTD you see is what you get, the only thing to do is LEARN how far off your rig is, then adjust... this is why we ALL here suggest you buy a reliable 3rd party probe system to give you true pit temps and meat temps, this will save you more than you will ever spend on the extra probes.

Makes sense to me. Thanks

 

[Tallyman89]

Is there an accurate replacement probe? An upgrade?

 

[RayClem]

Is there an accurate replacement probe? An upgrade?

Not really, the problem is not that the probes are bad, but they are not located in the center of the cooking chamber. Most folks purchase a wired or wireless thermometer. There are plenty of options at varying prices. Although I do have a thermometer with four wired probes, I decided to drill a hole in the lid of my grill and install an analog thermometer like you might see on an offset smoker or gas grill. The one I got is large enough to see from several feet away.

https://www.amazon.com/GALAFIRE-Thermometer-Charcoal-Temperature-Replacement/dp/B07VG6M228/
I typically smoke at 225F which is the split in color between blue and orange on the dial. That makes it easy to verify that I am at the correct temp.

Please be aware that Traeger does not accept any third party thermometer results if you contact them. Also, drilling the hole through the lid is likely to invalidate the warranty.

 

[Tallyman89]

Gotcha. Thanks