Bosch HDI7282U Oven Heating Issue

e-spice

Premium Member
Joined
Feb 4, 2012
Messages
4
Location
Knoxville, TN
Model Number
HDI7282U/03
Brand
Bosch
Age
1-5 years
Hi,

I have a Bosch HDI7282U/03 oven and it has some issues heating that may or may not be related. The oven is approximately four years old and has always displayed these issues. My wife, who has cooked quite a bit using few different ovens (i.e. not a novice) has described the problems to me and I'll do my best to accurately convey them. She finally got tired of dealing with it and has tasked me to try to fix it! Here are the issues:

1. On regular (i.e. not convection) bake, it seems to bake cool. Her example is if a recipe calls for 25min @ 350F, it still will not be cooked at 45min. Due to this issue, she generally cooks using convection. If using convection bake on this oven, it is recommended that you subtract 25F from the recipe temperature. It will cook okay if you ignore this recommendation.
2. The oven seems very slow to heat. She said it will take about 35-40 minutes to get to 400F and will sometimes never reach 400F, hovering around 390F or so.

Would anyone have a recommendation on the next steps? I have a multimeter and could test whatever is recommended.

Thanks in advance for any help or suggestions!
 

rickgburton

Appliance Tech - Moderator
Staff member
Joined
Jul 11, 2006
Messages
33,498
Location
Murray, Utah 84107, United States
Bosch isn't a popular brand in my area but it sounds like the oven sensor needs to be replaced.

It should read 1100 ohms at room temperature. If you want, I'll try to locate a service manual for that model.

I just found the sensor is the same as other brands:
Oven Sensor 422089
Oven-Sensor-422089-01371774.jpg

[video=youtube;vWJOLFW2aw0]https://www.youtube.com/watch?feature=player_embedded&v=vWJOLFW2aw0[/video]
 

e-spice

Premium Member
Joined
Feb 4, 2012
Messages
4
Location
Knoxville, TN
Hi Rick - Thanks so much for that suggestion. I found the sensor, took out the screws holding it in place, and tried to pull it out. I wanted to pull it out so I could unplug it and test the resistance. It wouldn't come out far enough for me to unplug it though. I could probably pull it out but that will be tough due to the tight fit with some granite counter tops. Any idea if it has to be pulled out to disconnect the sensor?

Thanks again for your help.
 

rickgburton

Appliance Tech - Moderator
Staff member
Joined
Jul 11, 2006
Messages
33,498
Location
Murray, Utah 84107, United States
On all other brands, the sensor connects to the control board. If you can get to the control board you can check the sensor there. Most of the time the manufacturer takes that into consideration and they're usually designed so you can pull the sensor and sensor connector through the hole where the sensor mounts. Then disconnect it but put some tape around it so it doesn't fall back through. If you can't get to the sensor connector, pulling it out might be the only way.
 

e-spice

Premium Member
Joined
Feb 4, 2012
Messages
4
Location
Knoxville, TN
On all other brands, the sensor connects to the control board. If you can get to the control board you can check the sensor there. Most of the time the manufacturer takes that into consideration and they're usually designed so you can pull the sensor and sensor connector through the hole where the sensor mounts. Then disconnect it but put some tape around it so it doesn't fall back through. If you can't get to the sensor connector, pulling it out might be the only way.
Ok - I had to pull out the oven to get to the sensor connector. It measured 1112 ohms at room temperature. Is this within the limits of normal or should I consider replacing it? If this is normal, do you have any other suggestions to check?

Thanks again for any help. I do appreciate it!
 

rickgburton

Appliance Tech - Moderator
Staff member
Joined
Jul 11, 2006
Messages
33,498
Location
Murray, Utah 84107, United States
OK, here's where we're at; Because I have no reliable sources for Bosch service information, I can only tell you what might be causing the problem you're having based on similar problems with other brands. I believe you are having a temperature issue with your range that gets a little better when the fan is on and blowing the heat around but even then the temperature is not correct.

We can rule out the bake element and broil element. Range elements are like a light bulb, they're either good or bad. Double check both elements. If they turn on, they're good. 90% of all temperature issues are due to a faulty oven sensor. The other 10% are the electronics. Your oven sensor is testing good and although I haven't ruled it out, it sounds like your problem could be in the electronics.

The Oven Control Board is a very expensive part so this what you need to check; First, you want to confirm the problem is temperature related. You need an fairly accurate way of testing the oven temperature with fast response. Don't waste your money on those supermarket thermometers you hang on a rack. They won't work. My DMM has a temperature scale that I use to check temperatures. See if your meter has the same. A quality meat thermometer might work but usually don't go high enough to check oven temperatures.

Put your DMM temperature thermocouple in the center of the oven. Close the door and check at 250*F, 350*F and 450*F. Start with a cold oven for each test. If the temperature is off by 50* or less, most ERC's have a calibration setting built into them (figuring it out for Bosch might be another story). You can also test the oven sensor at those temperature. When your meter says the oven temperature is 250*F the sensor should measure 1450 ohms. At 350*F- 1650 ohms; At 450*F- 1850 ohms.

That's about the best I can do for you unless I find better Bosch information.:)
 
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