How often should microwave ovens be replaced?

Most microwaves are built to last around 15 years. Of course, it depends on how much use it gets and how well it is cleaned and maintained. Because of the high cost to repair them and new advances in technology, most people choose to buy a new one instead of repairing their old one. I just replaced my 24 year old microwave because I'm doing a kitchen remodel. Even after daily use, my old one works great, so I will probably donate it to a food kitchen. Over the years, the price of microwaves has come down so a lot of people replace them based on the newer models rather than because they are warn out.

There are three likely reasons one might replace a microwave oven: (1) if it fails to heat (2) if it leaks radiation (3) if it causes changes in the food, thereby rendering the food unsafe.

1. If the oven fails to heat, you'll know easily enough.

2. Some people are concerned with being exposed to the microwave radiation. The U.S. legal limit of leaking radiation is 1 mW/cm² at 5 cm (about 2 inches) from a new oven — for a used oven the allowed radiation is five times higher. It is rare for an oven to exceed these limits. As a comparison, a GSM mobile phone may emit up to 1 W at 1800 MHz, which is 3.2 mW/cm², at 5 cm, with a human being staying nearby (such as within 5 cm for far longer periods of time). Whether or not cellular phones are hazardous to the health is also controversial (see mobile phone radiation and health).

Microwave ovens produced after 1971 must meet the Food and Drug Administration safety requirements for radiation leakage; less than 5 mW/cm² at 5 cm from the surface of the oven. This is far below the exposure level that is currently considered to be harmful to human health.

The radiation produced by a microwave oven is non-ionizing. As such, it does not have the cancer risks associated with ionizing radiation such as X-rays, ultraviolet light, and nuclear radioactive decay. Any cancer risk from microwave ovens would necessarily occur by an unknown mechanism. Such a mechanism, if existent, would also need to be far weaker than that for ionizing radiation, since long-term rodent studies of a type which easily identify cancer risks of ionizing radiation, have so far failed to clearly identify any carcinogenicity from 2450 MHz microwave radiation at chronic (large fraction of life span) exposure levels, far larger than humans are likely to encounter even from leaking ovens.

3. The possible negative effects of microwaves on food is not well documented.

I've never heard microwaves becoming dangerous after any length of time. Mine is also 8 yrs old. I won't replace it until it doesn't work. Hopefully it'll last longer. My step mothers is 20 yrs old and she still uses it. I hope mine lasts that long.

Unless the microwave door has been damaged, you should not have problem using your microwave. Use it until is dies. The average life span of microwaves is 6 years.

Microwaves in workplaces do not last long at all. They get abused more, because everyone is in a hurry and they are used around the clock. You are lucky to have one last two years.

A Good Question.... Mine came with my apartment and I've been here for 14 years!

They can be used for as long as they are working.

Well when your pets start to go patchy and there are strange oozing pustules covering your body, you might want to invest in a younger, prettier model.

i had mine for 11 years then it stopped working so i brought another one

The only time I replace mine is when it doesn't work anymore.