KEMS308SSS05 Microwave is heating only intermittently

[eurban]

Model Number

KEMS308SSS05

Hello,

We have a 7ish year old Kitchenaid combination wall oven / microwave convection oven. Recently the microwave is only heating things occasionally. On the times that it doesn't heat, it sounds exactly the same as the times when it does. The fan comes on and it lights up inside but it simply doesn't heat its contents. Currently its takes 3-4 tries to get it to heat something in the microwave mode. BTW, the convection function for the microwave ovens seems to work just fine.

The door seems to close correctly and pushing it closed while operating the microwave doesn't seem to affect the the issue.

I have tried shutting off the breaker for 15 minutes and then restarting. No change.

I have also put the logic panel into diagnostic mode and there are no codes stored. The microwave door switch seems to operate as it should in the diagnostic mode.

I found the tech sheet for our unit online and I have attached it here in case it will help diagnostics.

I am hoping that someone can point me towards some likely culprits for my microwave's issues. I am able to remove the unit and test things with a multimeter. Any thoughts on where to start??

Thanks!

 

[rickgburton]

Put a cup of water in the machine for 2 minutes on high. Does the water boil?

 

[eurban]

I did as you asked

First, second and third attempts, the water was still cold (zero heating) after 2 minutes. The forth attempt, the water was very hot but not quite boiling. Keep in mind that when new, this microwave was not very powerful. As best as I can tell when it "decides" to work (like my 4th attempt this evening) it heats as well as it ever has.

Also as I mentioned before, you can't tell whether it is working or not until you open it up and check the item. It lights up, runs the fan and shows the count down timer and graphic on the screen regardless of whether it is actually heating or failing to heat the item.

Thanks!

 

[rickgburton]

OK see if this helps: https://www.facebook.com/ricksappliancerepair/videos/4436586865727/

 

[xdcai]

I have the same microwave with the same problem. Have you figured it out what's the cause? I think the problem may be the MW inverter or magnetron.

 

[Seangholi]

I did as you asked

First, second and third attempts, the water was still cold (zero heating) after 2 minutes. The forth attempt, the water was very hot but not quite boiling. Keep in mind that when new, this microwave was not very powerful. As best as I can tell when it "decides" to work (like my 4th attempt this evening) it heats as well as it ever has.

Also as I mentioned before, you can't tell whether it is working or not until you open it up and check the item. It lights up, runs the fan and shows the count down timer and graphic on the screen regardless of whether it is actually heating or failing to heat the item.

Thanks!

I have the same KitchenAid microwave oven combo KEMS308SSS05 with same issue. Any finding?