New 2009 WSM - Built in thermometer is so "wrong"


 
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euge.lee

TVWBB Member
I've had some issues maintaining high enough temps for smoking... with temps on the built-in lid thermometer always being lower than what I was targeting for my smokes. I removed and tested the WSM thermometer in hot water and it read just fine... 212F so technically, the thermometer works perfectly.

However... the WSM thermometer's reading cannot be used for "target temps" when using recipes and guidelines posted on TVWB because they aren't even close to what people are referencing if using different thermometers to read lid and grill temps.

Note: All thermometers were tested in boiling water and read proper temps.

So I'm doing some baby back ribs today and I'll be posting a few WSM, M-Grill and M-Lid temps throughout the cook in different "ranges" to show how different the readings are.

WSM = 2009 WSM Built-In Lid Thermometer
M-GRILL = Maverick ET-7 probe #1 at grill
M-LID = Maverick ET-7 probe #2 at lid

I did my last pork butt smoke off the Maverick temps and it turned out fantastic! The previous beef brisket smoke turned out way overdone and dry because I went off WSM lid temps... now I see why!

It did seem odd that I pretty much needed to prop open the already upside down door about a 1/2 inch to see temps of 240F or higher at the WSM lid themometer... I was probably smoking at an "actual" lid temp of ~280F when I did that!
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First reading... waiting for temps to settle as I follow the BRITU instructions.

<span class="ev_code_PURPLE">
WSM LID = 248
M-LID = 293
M-GRILL = 263
</span>

Here is the data plotted from my WSM showing the temperature differential between what the WSM reads and what the more common practice of "lid temps" via a probe in the top vent reads.

wsm.JPG
 
2nd reading is as follows....

<span class="ev_code_PURPLE">
WSM LID = 218
M-LID = 252
M-GRILL = 235
</span>
 
3rd reading is as follows... just added the ribs and allowed the temperature to rise back up for 15 minutes, still slowing rising back to my target temp of 225 (M-LID).

<span class="ev_code_PURPLE">
WSM LID = 185
M-LID = 218
M-GRILL = 207
</span>
 
4th reading... temps are stable and exactly where I want them.

<span class="ev_code_PURPLE">
WSM LID = 205
M-LID = 227
M-GRILL = 215
</span>
 
I am a new WSM owner and have only smoked on it three times. I think your numbers make alot of since. I keep shooting for 225 on the lid and it is easy to maintain that temp but has seemed hotter than 225 should feel. The water in the pan is a rolling boil,-I can hear the water boiling when standing ten feet from the smoker. It has just seemed far hotter than 225 in my OTG. Again I am new to the WSM. I will keep your numbers in mind during my next cook--thanks for sharing
 
Both of my WSM's are pre 2009 models so they came without thermometers. Both of them now sport big ole' easy to read Tel-True's.

I am a huge Weber fan, but it would be nice to see them equip their great smoker with a good thermometer. Seems that lots of folks have had problems with the thermometers that come with the grills/smokers.

In you case, what makes it perplexing is that you tested the thermometer and it tested out OK. I know that there can be some variations in the boiling point based on sea-level or whatever, but that still makes it a head scratcher!

Thank you for the informative post

Pat
 
In you case, what makes it perplexing is that you tested the thermometer and it tested out OK. I know that there can be some variations in the boiling point based on sea-level or whatever, but that still makes it a head scratcher!
Click to expand...

Yeah, it seems the thermometer is one of quality as it does read 212F on the dot in boiling water... the problems seems to lie with the placement and/or probe length I think.
 
great timing. I am using my new Maverick 73 and notice a great difference in the WSM lid temp. I do have a 2009 model and do not trust that lid temp. I am going to stick with the Maverick which i placed inside the top vent and left it hanging inside the smoker. Frustrating!
 
Cranked up the heat for the final stretch of the BRITU cook... results are as follows.

I don't think it should be frustrating... since the number of degrees off is relatively consistent. After a couple more test runs... I know what to look for on my WSM lid for what I want my true target temps to be.

<span class="ev_code_PURPLE">
WSM LID = 230
M-LID = 268
M-GRILL = 255
</span>
 
Glad someone else spoke of this as well. without my maverick I would be over cooking my food all the time. I agree, the lid thermometer is way off most of the time.
 
Good discussion guys... some thoughts... A good thermometer will measure the temp accurately wherever you place it. Just like in your home, measuring temperatures at different locations in your WSM will yield different readings. Also, as in ones' home, with its' thermostat, most smokers pick a thermometer location and make adjustments based on that one spot. Variations in locations/temps don't seem to make much difference....there's a smoke "range" indicated on most quality thermometers... and, yes, do use a remote probe thermometer to measure "doneness" that's what's important
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... No need ta measure with a micrometer only to mark it with chalk and cut it with an axe
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Originally posted by ron "Rondo" hanson:

Good discussion guys... some thoughts... Also, as in ones' home, with its' thermostat, most smokers pick a thermometer location and make adjustments based on that one spot. Variations in locations/temps don't seem to make much difference.... No need ta measure with a micrometer only to mark it with chalk and cut it with an axe.
Click to expand...

I agree, but since I'm a n00b, I count on using recipes as written... and when they ask for a 235 lid temp, I "used to assume" that the 2009 WSM lid thermometer could be used for that temp but it is now obvious that it cannot. 235F on the WSM lid is probably around 275F for those measuring at the lid using a remote probe.

It seems that when I do my regular "slow and low" smokes, I will be going for a WSM Lid temp of 205F. Anything other than that, I will insert my Maverick probe and go off those temps.
 
Originally posted by simon j:
Glad someone else spoke of this as well. without my maverick I would be over cooking my food all the time. I agree, the lid thermometer is way off most of the time.
Click to expand...

Well, the "silver lining" is that it's not off most of the time, it's off ALL OF THE TIME in a very consistent manner. So you just need to do some math to know what your target is on the built in WSM lid and go from there for your basic everyday smokes.

As I've posted above, I'll be shooting for 205F for my slow and low cooks.
 
Originally posted by euge.lee:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by simon j:
Glad someone else spoke of this as well. without my maverick I would be over cooking my food all the time. I agree, the lid thermometer is way off most of the time.
Click to expand...

Well, the "silver lining" is that it's not off most of the time, it's off ALL OF THE TIME in a very consistent manner. So you just need to do some math to know what your target is on the built in WSM lid and go from there for your basic everyday smokes.

As I've posted above, I'll be shooting for 205F for my slow and low cooks. </div></BLOCKQUOTE>

indeed, ALL of the Time :-)
 
Agreed!
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Many use only the Weber or Tel-true, etc., dome therm temp and tune for the lower portion of the indicated smoke range..generally close 'nuf...if ya only have a single probe remote,like me...not much choice
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Lets get ta smokin
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It's true. My Weber therm is nearly 30*F off. My Maverick ET-73 reads accurately that much hotter. It's good to know, but not something to sweat over. As Rondo says, "mark it with chalk and cut it with an axe." I like that. Patience and testing for tenderness is the key.
 
It looks like your numbers are off only 15-20F degrees but the factory thermo is reading lower than the grate. I was expecting it to reed a little higher than the grate temp. This means during my first cooks temps were likely 30+ degrees hotter than I expected. In my OTG the grate temp is usually a little lower than what I read on the lid with my deep fryer thermo. My results were great in my first three cooks, so those higher temps luckily caused no problems. I will keep your numbers in mind for future cooks until I can afford a probe-type thermo. Thanks again for posting your results!
 
I believe the stem on the Weber therms are too short.

When I first did the Tel-Tru mod on my old 18.5", I used a BQ300 with a 2.5" stem and found my temps at the lid were ~20 degress off from my temps at the top grate. I then switched to a 4" stem and my lid temps are within 5 degrees of my top grate.
 
my 2 cents:

its tough to get an accurate cooking temp in the wsm, as air will be hotter on the outside than in the center, and it will vary slightly from bottom to top.

with that said, it doesn't make sense for weber to charge you for a better therm that won't be more accurate (just different).

people use to kill brinkman for putting a therm in the ecb that read: "hot, ideal, cold" rather than actual degrees. So weber put degrees on their therms and people are still grouchy.

I was once there with you all too, at that point when the wsm was new and things weren't going right, trying to follow time and temps. I had wires all over my wsm trying to figure out actual temps. The first eureka came when I realized temps aren't always what they seem, but the second and big one came when I stopped caring about the actual temp.

Be patient friends, good bbq comes from trial and error not by following time and temps. Keep cooking and know that eventually a $5 therm stuck in your vent damper will be all you need.
 
Originally posted by euge.lee:
when they ask for a 235 lid temp
Click to expand...

If I saw a recipe stating 235 degrees for a smoker, I'd interpret that as meaning they were too lazy to write "225 - 250".
 
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