Bosch HBL3450UC Sizzling Sound & Smelly Smoke

[baumgrenze]

I 2010 we remodeled and redid the kitchen. We installed a built-in Bosch HBL3450UC. This afternoon as it was warming to 400F to bake some potatoes it made a sizzling, a pop, and much smelly smoke.

If these new high tech ovens have a main heating element, my guess is that it shorted.

1) Is this a DIY project for someone who replaced multiple elements in the 2 ovens in the 1955-1965 vintage GE Liberator (Model J-408) electric range we inherited when we bought our house. Of similar vintage and provenance is our GE V-12 dryer which now approaches the classic Norwegian family axe with 3 new heads and 15 new handles, but it still runs fine.

2) Is it true that replacement control components for an oven like the Bosch HBL3450UC are prohibitively expensive and even more challenging to replace?

3) Is it true that at 8 years of service with little-or-no repair expense our 'new' oven may well soon need further repair?

4) Should we conclude that we've been fortunate in the service we've gotten? We've probably done only 3 self cleaning cycles, but we do a lot of baking and low temperature drying, say split figs at 135 F overnight.

Advice please Mr. Samurai.

baumgrenze

 

 

 

 

[baumgrenze]

Here are some more details:

The full model number on our oven is:

Bosch - Wall Oven - HBL3450UC/08

One website that lists parts gives this part number.

AP4017056

I find this alternative also:

00144648   Bosch Thermador Oven Heating Element part number 00144648   (Bosch, Gagenau, Thermador)

After a night's reflection, I have a significant question:

Is there a failure type for an oven element in which the element 'shorts' and fails with a popping sound and a bad smell like burning wiring?  (In my 55 years as a house-holder I vaguely remember such a failure.)

Together we are concerned that this might have been an 'unusual' element failure which also overheated the wiring to the element and/or the oven control circuits.

When I shut off the power to the oven at the service entrance the 240V double breaker was not tripped.

Are there other questions I should be asking.

PS, we are 3,100 miles from New London on the San Francisco peninsula. Clearly that is too far to open a service call.

baumgrenze

[J5*]

Most likely a bad heating element 

a visual inspection will likely identify it 

depending on your diy skills it’s quite achievable to replace it 

[baumgrenze]

Thank you, J5*, for your kind response.

I'm struggling with vision problems associated with a recent retinal surgery.

I searched for a 'tutorial' (I prefer sequential images to a video because of hearing aid issues.) I've not found a link showing how to gain access to the heating element so I can visually inspect it.

Is there any chance you, or another reader, can supply a link to such a tutorial and/or a YouTube video?

thanks

baumgrenze

[baumgrenze]

I have the bake element removed. I can see no sign of physical damage. There is continuity across the connection terminals. The resistance across them reads 26.4 oms. The 'nameplate' reads 2000W at 240 V, so this resistance matches 2000W at ~230V so it is in the ball park. I think it is a sound element.

On the other hand, the control board is a mess.  I have save images in Imgur. They should be at the URL below. I tried to use Insert other media and the bar turned pink and it failed. It is past bedtime and time to send this as is:

https://imgur.com/a/u2BNU3g

Any idea what would have caused such a catastrophic failure?

thanks

baumgrenze

 

[Budget Appliance Repair]

Just something that can happen when the relay severely overheats from bad contact points and/or bad solder joints on the board at relay solder pins on the back trace side of board.

Most likely no other damage and replacing the board will fix it.

[baumgrenze]

Willie,

Thanks for the reassurance.

Is there any point in hassling Bosch that it is better I tell them about this failure than if I present it on Facebook as a 'fire averted when my oven control board failed?'

I know, they limit their guarantee on parts in a new appliance to 1 year even if that failure 7 years out can be shown to be the result of a bad solder joint on a control board.

My point is it is 'bad optics' to have a customer point out the risk of fire from such a failure.

Thanks again,

baumgrenze

 

 

 

[baumgrenze]

I should have been more upfront in yesterday's post.

At 18 months from turning 80 I called in a repairman. I'd asked them to buy the oven element, understanding that they could not/would not return it, so it hot replaced. I learned by watching how it is installed. Given my description, do others agree that the element that came out is probably still good. If the new one fails, that it could serve as a replacement?

In watching I also learned that there is a small squirrel cage fan that cools the control-board area of the oven. It was 'greasy' and the repairman dutifully cleaned it with a brass brush. He assured me that it will last a little longer and that when it slows down too much it will throw a control code reporting that it needs to be replaced.

Where is the intake for this fan? I'm trying to understand how grease got into it. It does not make sense to me that it should be inside the hot oven, yet that it the most likely source of greasy air, e.g., from the baking of pizza at 500 degrees F.

Thanks to everyone for your insights and encouragement over the years,

baumgrenze

 

[baumgrenze]

I had a minute this afternoon, so I released the failed Control Board from its metal base and took some photos. I've uploaded an overall image and a close-up of the failure area.

They look instructive to me. It appears that there was an 'explosive' short right under what I take to be the oven element relay.

What do the experts see?

https://imgur.com/a/ZRcRyMN

Thanks,

baumgrenze

[Budget Appliance Repair]

Typical looks of one that complete burns out.

As long as the wiring isn't burnt, (OK and can be wiped off if just soot from the plastic relay cover burning).

The bad solder joint was holding just enough to cause major heat from all the bad contacts and weak solder joints and keeps passing enough power through the weak/bad connections generating more heat and if this goes on long enough without going completely open circuit eventuality something going to start smoking and then fire.

Replacing the board should take care of your problem, just make sure to clean and make sure the terminal on the wire that was on that relating connector isn't damaged.

[baumgrenze]

Thank you, Willie, for confirming my concern.

Is it true that Bosch is 'off the hook' for a poorly soldered PCB card since parts on a new oven are only under warranty for 1 year and this one lasted 7?

thanks,

baumgrenze

 

[baumgrenze]

FWIW, I set up my tripod and used manual focus on my Canon A590IS point-and-shoot camera. I even used the self-timer to trip the 'shutter' to minimize the shake.

Here's a link to some sharper close-up photos of the control board at the failure point.

https://imgur.com/a/zK2yZ7S

Thanks

baumgrenze

[Budget Appliance Repair]

Unless your warranty info in the owners manual says any different, it's 1 Year Parts & Labor.

The only other case where it may be under the manufactures warranty is if there was some kind of safety recall for this problem.

Bosch dishwashers had such a safety recall in 2009 and will still replace the control boards in the effected dishwashers if you know to call them about it or if you have a service company look at it and they are aware of the safety repair/recall, but only for specific models listed in the recall.  Some of the newer ones that aren't listed in the recall are still having the same/similar problem with the heater relay solder joints breaking/burning loose and causing the heater to stop working.

[LearningTech]

On 11/18/2018 at 10:11 AM, baumgrenze said:

Thank you, Willie, for confirming my concern.

Is it true that Bosch is 'off the hook' for a poorly soldered PCB card since parts on a new oven are only under warranty for 1 year and this one lasted 7?

thanks,

baumgrenze

 

Only thing you can do is report to CPSC.GOV they handle recalls. If they get enough complain on same issue they will do something.

the bosch recall that was spoken of  was all started cause someone reported it, and  others did too. I believe the report said only 11 confirmed fires resulting from the bad controls.

do that and if others have an issue they may start a recall, but for you now. Unless you want to higher some dang good lawyers. Don’t bother.