Jenn-Air Broiler Fan Runs Constantly

[Longbow]

Re: Jenn-Air Broiler Fan Runs Constantly

Relay: Yes the relay runs the fan and it turns off and on, just not at the right times. Supposed to come on @ 500 degrees, which is during broiling or oven cleaning. Instead, it comes on at about 250 degrees and keeps running until the oven is almost cold - then it shuts off.

I've had that main board out on my bench several times and probably replaced everything that looked like it would be sensitive to heat. These days, temp sensors come in all sorts of packages, so I'll give it another go with freeze spray, but I think I already did that a few years ago.

uPC crystal is a good thought. Usually you find the 37KHz bus crystals give you the most trouble. The crystal (or tuning caps) could also be the cause of erratic error codes that don't relate to anything. A part that changed value is also likely. The official fix is to order the "new style" controller board with a metal heat shield that goes between the board and the oven. If the oven hasn't been used, I guess that's why the controller board hasn't acted up.

One more important thing on this oven type. Don't spray cleaners like Windex around the touch pad. The fluid creeps into the touch pad flex connector and the membrane, ruining them.

[bluto]

Re: Jenn-Air Broiler Fan Runs Constantly

I have previously replaced the two caps (a filter cap and one smaller value cap IIRC) on my oven's controller board without removing the board from the oven. I didn't feel like disconnecting what seemed like 50 wires running to it from all over inside the oven. So I really didn't get a good look at what makes that board tick. Thankfully I have not had the fan problem yet. It may help that I use my oven very rarely.

Perhaps you could take a picture of your controller board for our experts to look at. I would definitely replace the two caps on it. I would also look out for the presence of another micro-controller on that board (you mentioned serial comm between the two). It may have a ceramic resonator that is going wonky. Also I remember that when fooling around with my clock module when the oven still had power, the fan would activate soon after the clock module was unplugged from the controller board. So there could be some bad connections between boards or even bad solder joints that are causing these symptoms in your case.

[mockingbird]

Re: Jenn-Air Broiler Fan Runs Constantly

I am an ignoramous, but maybe the relay is broken and always set to on?

[Longbow]

Re: Jenn-Air Broiler Fan Runs Constantly

Actually, the broiler fan problem HAS been confirmed to exist on the main controller/relay pcb. But, I would like to get a handle on how to fix it at the component level. Someone out there knows about it, I'm sure.

[Longbow]

Good thread on the dim Jenn-Air clock. I had to do this repair a few years back as well. Now for another well-known Jenn-Air problem that has not been figured out (as far as I know). The same models that have the dim clock also develop quirky problems with the main controller board. Intermittently, you will get an error code that starts up for no apparent reason. Pressing the Cancel/Off button stops it and away you go.

But the real irritating problem that develops in these units is that the broiler fan starts running all the time. Actually, the fan starts up at a very low temperature, far below the 500 degrees that the manual states as normal. This fan is designed to keep the space between the cooktop and the oven cool when the broiler is turned on (or if the oven is in self-cleaning mode).

The fan is turned on by a relay on the relay (controller) board. Obviously, there is a faulty sensor somewhere that knows when broil/clean is on, and 500 degrees has been reached. An obvious place to start is the main oven thermostat, but that's not it (replaced years ago). I've been all over the controller board replacing electrolytics, resoldering, checking for leaky parts without any luck.

It is possible there may be some kind of sensing in the timer pc assembly, since that board is actually located in the space that requires cooling. Since there is already a track record of the display caps failing, I may go in for another close look at the timer. There is actually serial data being exchanged between the timer assembly and the controller board so its not so simple.

Has anyone been successful with the well-known broiler fan problem?

Thanks!