Microwave oven testing?

Please no lectures on SOP, liability or…

Are you aware of a standardized test for residential microwave oven equipment?

AHS is refusing another clients request for repair.

What test method do you use?

Here’s what I have from some manuals:

Please check the following before calling for service:

  1. Place one cup of water in a glass measuring cup in the microwave oven and close the door securely.
    Operate the microwave oven for one minute at HIGH 100%.
    A Does the microwave oven light come on? YES _____ NO _____
    B Does the cooling fan work? YES _____ NO _____
    (Put your hand over the rear ventilating openings.)
    C Does the turntable rotate? YES _____ NO _____
    (It is normal for the turntable to turn in either direction.)
    D Is the water in the microwave oven warm? YES _____ NO _____

I DO NOT inspect portable appliances and my agreement states that. Only built-in appliances such as Stoves, Wall Ovens, Dishwashers, etc.

If it can be moved, it’s not inspected.

95% of the microwave ovens I encounter are built-in and usually include the range hood and stove light. I use Mr. Microwave Magic Lights for $6 ea from http://www.electronix.com/catalog/product_info.php/cPath/238_260/products_id/5445






I use a device similar to Mike’s and Nick’s - a microwave leak detector.

The tribbles actually exist?

InterNACHI member Phil Gage’s wife makes them for us. We’ve shipped many thousands of them over the past 2 years.

A hamster wrapped in electrical tape on high for 3.5 minutes. If it cooks without exploding it passes.:mrgreen:

Dang it Manny!, now everyone knows the secret to making the tribbles: http://www.nachi.org/tribbles.htm :wink:


I’ve tried the Tribbles but when you miss lunch they don’t taste so good warm! Now hamsters with a dash of Tobasco, Ummm Yummy!!:slight_smile:

Actually send me some tribbles. Do these cost much to make with the NACHI logo on them? They would make great ice breakers when giving presentations or speaking in groups, etc.

Tribbles and blinking lights do not tell the client anything about measurable heating whether the unit is or is not functioning properly. Not like setting an oven a 350°F

I’ve always said a cup of tap water for 1 minute at high should be at least 120°F otherwise just wait for the sink supply in most homes.

I also carry microwave popcorn and will pop a bag for function and snacking on vacant properties and will ask permission on occupied.

The issue on this one instance is a $900.00 unit that requires repair or replacement and the warranty co. does not want to honor their agreement. I was just curious what test methods were used by others.



For the most part a microwave oven is either on or off. No in between.

Power levels are manipulated by percentage of on vs. off time for most microwaves.

You can read all about it HERE

Here is an INDEX

IMHO, if it blinks the tester lights, heats the tribble or pops the popcorn it’s working as far as an HI is concerned.

Have a great New Year of 2008:-)

Warranty co. says my 1 minute test along with the NACHI light tester is inferior and should be tested on high for 2 1/2 minutes this should boil water 212°F in most units
Unit in question will only get to 200°F by their own time and test,
“but that is close enough” they say.

Glad I don’t have to eat their cooking


How hot the water gets after 2 1/2 minutes depends on:

the starting temp of the water

the power output of the microwave

Power level setting of the microwave

I have had both low and high power microwaves.
Perhaps your client is just used to a different type of unit.
It takes some getting used to going between the units.

I have the same problem between my travel trailer and the house. They do not act the same.

Find out the mfg. rating for the microwave in question.

What are these things filled with? I was using mine yesterday and it started to pop like a bag of popcorn. Smelled like it too.

I use a tester then a cup of water to check for leaks around the door if the light blinks in all zones then i good to go. The water is usually hot after i check the door for leaks.
Warranty companies love to hang home inspectors . Gets them out of claims. Past the old buck.

I do like this idea though

Mine’s never popped, but it sure smells like popcorn!

Barry, I am at a loss…I don’t know what you can do to “measure” how well the unit is working. I just check for leaks and see if it warms up the tribble…it is hard to quantify how well a microwave is working. Hope it works out for you and your client.

I don’t care how well they heat, the most important test is a leak test, and it can only be performed a meter by a Certified Microwave technician. Anything over leakage .0025 Picocuries is unsafe. Most leak around the door seal, and if you see any cracks anywhere, it is an automatic failure. Any of the old Amana Radar ranges, leak like a sieve and are known to cause cancer in any home owner unfortunate enough to have owned one of the originals. As a matter of fact, heating and cooking by microwaves was discovered by a Radar operator at an Air Force installation, who had a sandwich in the pocket of his Smock, about waste high, the sandwich got hot, hence the original name for the Amana Radar Range. I suggest you include language in your reports that you tested for operation only, and recommend a leak detection test by a qualified Appliance Tech with the appropiate certification, to CYA. P.S. Never stand in front of one that is in operation.

I have my assistant who has a pacemaker stand next to the unit. If he goes tits up after a few seconds I know there is a problem. He hates doing this and always groans when he sees a built in microwave.:wink: