Microwave is being wonky

[clifffaith]

We have a microwave/vent fan over our electric stove top. I was heating dinner tonight, and the first plate heated as usual. The second plate heated, I took the plate out and closed the door, then the microwave immediately started making noises like it was running. Opened it back up, hit the stop button, closed the door and once again it sounded like it was running. Put a cup of water inside to make sure it wasn't actually heating, water came out cold. Later in the evening it heated two cups of coffee as usual, but we have to keep the door ajar when we're done to stop the "running noise".

I thought tomorrow morning we might go out and flip the circuit breakers to see if that resets it. Anyone have an idea as to why this is happening or what we can do ourselves for a quick fix?

 

[am1]

We have a microwave/vent fan over our electric stove top. I was heating dinner tonight, and the first plate heated as usual. The second plate heated, I took the plate out and closed the door, then the microwave immediately started making noises like it was running. Opened it back up, hit the stop button, closed the door and once again it sounded like it was running. Put a cup of water inside to make sure it wasn't actually heating, water came out cold. Later in the evening it heated two cups of coffee as usual, but we have to keep the door ajar when we're done to stop the "running noise".

I thought tomorrow morning we might go out and flip the circuit breakers to see if that resets it. Anyone have an idea as to why this is happening or what we can do ourselves for a quick fix?

Probably best to buy a new one.

 

[isisdave]

Does it sound like the fan continues to run? It could be an internal heat sensor that thinks the microwave is still too hot and the fan needs to run.

I've seen microwaves where the fan is normally controlled by heat; it doesn't come on for a little while after starting, and continues a while when the cooking is done.

 

[klpca]

When ours did something similar (just didn't heat the food) it was a pretty inexpensive repair - maybe $100 +/-. Ours is a micro/convection combo so it was pretty expensive new and worth fixing.

 

[DaveNV]

Mine has an automatic fan that comes on when it decides things are too warm. Yours may be doing the same. Depending on the age of the unit, replacement may be cheaper than repair.

Dave

 

[clifffaith]

Woke up hoping the situation had resolved itself. Nope. Heated up the last cup of coffee from last night's pot -- quite disconcerting to have the microwave "going" as soon I close the door and before I've punched in the time. Cliff got up later and heated water for four minutes, fan kept running. Then it was time to reheat my cup for 30 seconds. Micro went quiet as soon as my cup was done! We hope it has regained its composure.

We are gone a week, back a week, gone a week for the rest of October, so I'm glad that (fingers crossed) pet sitters won't have to deal with a wonky machine. A new one becomes a "project" because it is also means disconnecting and reconnecting the stove top venting system. Sucker fan has been extra noisy for the last couple years when we use it while venting bacon or sausage cooking. We inherited it when we bought the house in 2010, don't know how old it is. I suppose it will be one of those things we have to replace before or during a home inspection for selling.

 

[DaveNV]

Woke up hoping the situation had resolved itself. Nope. Heated up the last cup of coffee from last night's pot -- quite disconcerting to have the microwave "going" as soon I close the door and before I've punched in the time. Cliff got up later and heated water for four minutes, fan kept running. Then it was time to reheat my cup for 30 seconds. Micro went quiet as soon as my cup was done! We hope it has regained its composure.

We are gone a week, back a week, gone a week for the rest of October, so I'm glad that (fingers crossed) pet sitters won't have to deal with a wonky machine. A new one becomes a "project" because it is also means disconnecting and reconnecting the stove top venting system. Sucker fan has been extra noisy for the last couple years when we use it while venting bacon or sausage cooking. We inherited it when we bought the house in 2010, don't know how old it is. I suppose it will be one of those things we have to replace before or during a home inspection for selling.

My microwave is one of those over-the-range styles. It also vents the range. The vent connections were very simple, and the whole thing has a grounded three-way plug that plugs into an outlet in the cupboard above the microwave. Easy in and out.

Dave

 

[Firepath]

Is the microwave old? Are you having any other problems? Could be something going on with your power.

 

[clifffaith]

My microwave is one of those over-the-range styles. It also vents the range. The vent connections were very simple, and the whole thing has a grounded three-way plug that plugs into an outlet in the cupboard above the microwave. Easy in and out.

Dave

It is heavy and looks like a two person job to be sure it isn't dropped on to the stove top. We'll buy a new one at Lowe's when the time comes and let them install it.

 

[clifffaith]

Is the microwave old? Are you having any other problems? Could be something going on with your power.

Don't know how old it is (we've owned house 8 years). The sub zero is over 25 years old, so unless they had to replace micro at some point I suspect it and the double oven are also that old. We had to replace the dishwasher last Christmas. Everything else (except the alarm back up battery which of course dies just before we are leaving town and Cliff is on his way to alarm co for a new one) is running fine so I don't think it is a power issue (although we've had those in the past and cleaning ladies can't run two vacs. at the same time).

 

[Talent312]

I would try hitting it with a hammer.
I did that last night to a rocker light switch stuck in the on position.
It seems to have worked. The light turned off.
.

 

[WinniWoman]

Ours is 6 years old- over the range one also. With ours, if you kind of lean a bit down on the handle when closing or opening the door it comes on! It has done some other weird stuff as well.

When we remodeled out kitchen 6 years ago and bought this microwave- and had electricians here as well- it worked great for like a year and then suddenly it stopped working. Come to find out all of a sudden it was tripping the breaker. We had to get the owner of the electrical company back to come in and he replaced a thingamajig at the breaker box, but supposedly it really proper practice (code) what he did. He claimed it would be just fine and it has in that it is not tripping the breaker any longer.

I had posted about this on TUG and on Facebook (via other electricians) at the time. Bottom line is after listening to all their input, I just try to be careful not to run anything else on the line simultaneously that the microwave is on- like the vacuum cleaner. Really- it is only the outlets in the dining room and living room that are on it- so just some lamps or the vacuum. We are rarely in those rooms anyway.

 

[pittle]

Mine is not over the stove, it is built-in and the fan runs after you use it. I just keep hoping that it will die and I can buy a cheaper one that does not need to cool down longer than it takes to pop a bag of MW popcorn! When we bought our house in 2008, the previous owners took ALL of the built-in appliances (it was a foreclosure and the appliances were less than 2 years old) so we had to by new ones to fit the spots - I certainly chose the wrong MW!

 

[WinniWoman]

The best one we ever had was one we got when first married in 1977. We used it until 6 years ago when we remodeled the kitchen! It was a GE stand alone. Was still working great when we sold it for $25 to a mom for her boy's college dorm room!

 

[pittle]

The best one we ever had was one we got when first married in 1977. We used it until 6 years ago when we remodeled the kitchen! It was a GE stand alone. Was still working great when we sold it for $25 to a mom for her boy's college dorm room!

We bought our first one in 1977 too. I think it was a GE and weighed a ton and did a marvelous job. We gave it to our son & his wife in 1996 and they used it for several years before remodeling their kitchen with one of the over the stove ones. Appliances used to last for a long time with very few issues - now they seem to have a 7-10 year life.

 

[Talent312]

When I dispose of old appliances, if I think it won't go for MT $100,
I'll give it away using the local freecycle group. https://www.freecycle.org/
.

 

[BJRSanDiego]

I suspect that the problem may either be a sticking relay (that controls the fan) or something on the control board that controls the fan motor and possibly turn-table. If you aren't comfortable taking the unit apart, safely bleeding off the high voltage, and troubleshooting to the module or component level, then it is time for a new microwave.

We have a microwave that came with a kit to make it look like it was built in. So, when my microwave crapped out (no heat) I was concerned with how to replace it. Of course, the microwave ovens have all changed sizes. The new "built-in" kits are also different sizes. So we would have a cabinetry issue. I troubleshot the problem down to the Magnitron (the "tube"). It cost me $75 to get a replacement. But, I was trained as an electrical engineer and am used to troubleshooting circuitry. (Also, Youtube videos helped).

There are potentially some lethal voltages inside of a microwave. So if you are not 100% sure of what you are doing, you probably shouldn't tackle it.

 

[clifffaith]

How funny, I was looking for something else and came across this old post of mine. Funny #1: I have no independent memory of this. Funny #2: Last week the old microwave started doing the opposite. Instead of the fan blowing when the door is closed but the oven off like it did briefly 18 months ago, it now blows as soon as the door is opened. Scares the hell out of me every time. One more thing for the "selling the house" list.

 

[CPNY]

Got rid of my microwave years ago and next looked back. Convection toaster oven reheats perfectly. Boil water or liquids in a saucepan.

 

[TheTimeTraveler]

How funny, I was looking for something else and came across this old post of mine. Funny #1: I have no independent memory of this. Funny #2: Last week the old microwave started doing the opposite. Instead of the fan blowing when the door is closed but the oven off like it did briefly 18 months ago, it now blows as soon as the door is opened. Scares the hell out of me every time. One more thing for the "selling the house" list.

The good news is that "over the stove" microwave ovens have come down substantially in price over the last five years, and you should be able to pick up a nice model for a very good price.


.