Thermador Fast Preheat - why not do it all the time?

19 years ago

I just got a Thermador oven, and am wondering why Fast Preheat isn't the default? Does it shorten the life of the oven? Use more gas? Occasionally explode?

Featured Answer

jakvis

19 years ago

A fast preheat in an oven does not guaranty that the oven is truely heated to your intended temp.
Some ovens this is only a timing feature and after so many preset minutes the indicator "dings" even though the oven is not to the set temp.
Other ovens turn on addition elements to speed the process. This gets the air temp to the set temp but maybe the oven walls and door are not up to the set temp.
There are ovens that turn on addition elements and run the convection fan during preheat. These do a better job of getting the walls and door hot along with the air.
Some companies base their advertised preheat times on lower temperatures.
BUT...
In all reality with the physics of thermal dynamics, and a household range, you can not truly heat an oven to 350 in 5 minutes.
Depending on the set temperature, it takes 20 minutes or longer for all the surfaces in the oven to stabilize.

Many of my customers who do a lot of fine baking like pastries, breads, etc., let their ovens heat for well over 30 minutes before putting in the product.
Commercial bakers turn their ovens on several hours before baking.

However like mentioned in the above posts there are sometimes when you don't want to preheat at all.

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Comments (12)

rivendell
19 years ago
Good question! What do you think of your new oven? I have one on order...
jayne s
19 years ago
I can think of cases where you have recipes that call for putting the food into a cold oven and then turning on the heat. I've got a couple of recipes like that.

There must be other reasons.

jayne
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dockside_gw
19 years ago
My 8-year-old Kenmore wall oven heats up in about 5 minutes. My daughter's new Thermadore oven takes at least 20 minutes to heat up. Drives me nuts. Besides the additional energy it must take, you have to turn it on, oftentimes, before you even start to prepare what goes in it.
coolvt
19 years ago
Some are made to go on preheat automatically every time they are turned on and others have a separate preheat setting. As to why some are automatic and other aren't....not sure why;-)
bretonb
19 years ago
I know what you are talking about. I recently had a Kenmore Elite electric range. In the manual it described either using a bake or roast option without preheat or using a preheat cycle. To make matters worse it did not say the preheat cycle was faster than the other. So , I may be stupid, but why do you need two cycles. Why not always use the preheat. The only thing that was different was that the preheat option beeped when it came up to temperature. Sometimes I think they put all these buttons on a range just to make one think there are special features. Humph!!!! Did you actually time the preheat time to the other way with no preheat? Or does yours not tell you when it gets up to temperature when you are not using preheat?
hannah_ma
19 years ago
Also it can depend on the size of the oven itself. In the larger ovens you may need some extra help heating up the space in the same time as a smaller oven.
jono123
19 years ago
I have a Thermodor 27in (double) and often wondered why fast preheat is not the only setting. Here's my guesses:

- uses more energy to fast preheat then not
- as mentioned, it takes awhile for oven walls, racks, etc to get to the same temp as the air and a longer preheat allows for more of the mass to reach temperate

Both are flat out guesses. Maybe they just needed something to do with the extra button on the touchpad.
solarpowered
19 years ago
The amount of energy expended for a fast preheat is a bit less than for a slower one, so energy usage isn't the issue.
PRO
Renaissance Restoration of Rochester LLC
7 years ago
It's the same reason some amps go to 11. It's just louder.
Linda John
2 years ago
Can you put a potato in the oven as it is on fast preheat? will it explode?
Linda John
2 years ago
Can i put a potato in my oven when it is on fast preheat?