Calibrating our electric oven using FireBoard

[Mosca]

I’ve been meaning to do this for a while. I get hung up on this stuff: I check calibration on my thermometers every spring, because the numbers don’t mean anything if they aren’t accurate. But electric ovens do that strange cycling thing, and over time you get an average temperature, not a steady temperature.

So I put the pit probe in the middle of the oven, set the temp to 350°, and let it run for 2+ hours.




On the first session, I wanted to see how long it took for the oven to hit 350° from 70°. When I read the FB average it was 350°, but that included the 15 minute ramp up. So I collected and calculated the mins and maxes by hand. I averaged the values: 381.6, 386.6, 388.3, 391.6, 388.9, 388.3, 338.3, 340, 340.2, 343.2, 342.5, 340, and got 364° average temp.

Then I ran the test a second time. This time, I waited until the oven beeped, signaling that it thought it was at 350°, and started a new session. This time, I let it run for a little over an hour, and then looked at the session summary:



And FireBoard says 366°. So it’s safe to say that my oven is running about 15° hot.

The fix for this is pretty simple. I can only change it in 10° increments, so I have a choice: I can have 350° displayed be either 345° or 355°. I’m picking 355°. Honestly 5° either way isn’t that big a deal. Neither is 15°, for that matter. But if I can get closer, and it’s easy, Why not?

So I knocked 10° off the oven, and ran it through a few cycles:



And at this point, if I cared enough I could just set the oven to 345°, figuring it’s 350°. But I don’t. Anyhow we are at 1710’ above sea level, so even though no adjustment is necessary, 7° might be useful there.

[Johnny Booth]

It seems to impact baking more than anything else.
Would having a heavy steel plate create a more stable Temperature?

I don’t have a fire board, but I have heard that it helps.

[SheilaAnn]

While I have a gas oven, I leave my steel in there all the time. Now I want to calibrate mine!

[Smoker_Boy]

A cast iron or griddle helps my oven reduce temp swings.
Not perfect, but better.

[Sweaty Paul]

I have done the same thing with my Fireboard. A few years ago we got new Jenn-Aire ovens right before Thanksgiving. I was tasked with making rolls (as per my usual assignment for Thanksgiving at our friend’s home). I made the recipe I’ve used for years twice and the results were well…edible and far from the usual delicious rolls that have been standard for a long time. As I was considering the problems it occurred to me that our new ovens might not be at temp. I tested the Fireboard and found it was accurate then tested both ovens and found them to be 50 degrees colder than the set and “showing” temp even accounting for the built in saw-tooth. I tested at 350 and the average temp was 300 swinging from 275-325. The best part of the Fireboard was the data was shown on the “cook” that I could take to the store from which the ovens were purchased. We got new control boards for both ovens. We had a similar problem two years later and the same test revealed we needed new control boards again.

Subsequently, I’m with Mosca and I check my ovens at least annually since I don’t trust the control boards anymore. The time is coming as cooler weather approaches. Would recommend.

Thanks for posting Mosca to remind me to get this handled again this year!

[barelfly]

My buddy leaves his heavy baking stone in his oven at all times for the heat sync.

But this makes me want to do the same on my oven. Perhaps this week since I’m not traveling!

thanks for sharing your info!