Replacing or Installing a Microwave Oven

Microwave ovens are wonderful features in most late model RVs.  Some RVs use a combination microwave/convection oven in lieu of a built-in gas oven that is part of the stove.  Any way you cut it, a microwave oven adds a lot of convenience when camping.  You can heat up water for a cup of coffee, tea, or cocoa in about 1 minute.  You can easily defrost frozen foods and cook entrés in a fraction of the time it takes in a conventional oven.   You just need 120 volt power -- from shore power, an on board generator, solar panels,or an appropriate sized inverter and a strong battery bank. If you don't have a microwave oven in your RV, you might want to add one.  But why would you want to replace an existing microwave oven?  There are at least three good reasons:  1) the old one has died, 2) newer microwaves are more powerful, and 3) newer microwaves are more energy efficient.  You may also want to upgrade to a microwave/convection combination for more capabilities and flexibility.

Microwave ovens have become an essential part of our lives, but I remember when they weren't.  We decided to get my Mom a microwave oven for Christmas one year, in spite of her strong protests that she "didn't need one" and wouldn't use it.  Turns out it quickly became one of her favorite appliances.  I'm sure we could all get along without one when camping, but who wants to?  I recently had to resort to baking potatoes in the campfire instead of microwaving like I do at home when our generator was out of fuel.  They turned out OK, but it took an hour instead of 10 minutes and some parts of the skins were blackened, a definite disadvantage if you like to eat the potato skins.

Replacing an existing microwave is usually easier than installing one from scratch.   In the first place, you already have an outlet to plug it into so you don't have to run new wiring.  Secondly, the cabinet has already been designed to support the weight of a microwave and probably has proper ventilation.  You may have to modify the opening to accommodate a different sized unit but at least you aren't having to start from scratch or make major cabinet modifications.  With any luck you will be able to find a replacement whose trim will fit the existing opening.

Does your microwave need to be replaced?   If your microwave stops working, it may need to be replaced but be sure to check the circuit breakers first and then look for internal fuses or breakers in the unit before you relegate it to the scrap heap and throw good money into a new one.  Another indicator a unit should be replaced is excess heat.   If any part of the cabinet is too hot to touch, the unit should be replaced before it causes a fire.  This is especially true if it gets hot even when it is not in use, which I have seen happen!  Another symptom justifying replacement is poor performance.  If it takes longer than it should for routine task, you should probably look at getting a new one.   Keep in mind most microwave instructions are based on a 1000 watt microwave and the older units in RVs may be less -- sometimes a lot less, like 650 watts.  Even in prime condition these low-wattage units aren't going to meet expectations.  If you have the budget for it you might want to consider replacing an older low-wattage unit with a modern model of 1000 watts or more.   If any of the major components have failed, it will probably be more cost effective to replace an old microwave rather than have it repaired.

Replacing a microwave oven is pretty easy, assuming you match up the opening size so you don't have to remodel the cabinets.   I recently had to replace a 25+ year old microwave that gave up in our Holiday Rambler Class A motorhome.  I found an RV-ready unit with a designated opening close to the existing cabinet.  The designated opening for the new microwave was 23 3/8 X 17; the existing opening was 23 3/4 X 15 7/8.  The trim more than accommodated the variances.  Installing the new microwave was a simple task.   It came with special baffles to allow it to be installed in a closed cabinet and they had to be attached to the unit along with the trim before it was placed into the cabinet.   Then it was a matter of plugging it in and installing 6 screws to hold the trim (and the microwave) in place.   I had considered purchasing a cheaper residential microwave oven but I was replacing a microwave/convection combination.  Our RV has a cook top without a gas oven, so the convection option was pretty important.   It took some searching on the Internet to locate a suitable unit within our budget.  Many were priced way out of my budget and others didn't match the installation opening size requirements.   But eventually I found one at http://WWW.PPLMOTORHOMES.COM that filled the bill.  Our old unit was only 650 watts.   The new one is 1000 watts.   Since most microwave recipes and cooking times are based on 1000 watt units, using the old one had its problems, even before it died.   Instead of 1 minute to boil a cup of water, it took two.  Microwave popcorn never did turn out very well . If you find yourself facing similar problems, you might want to upgrade even before your old unit fails.  There are many inexpensive residential microwave ovens.  The biggest problem with installing them will be securing them, ensuring proper ventilation, and creating a good looking trim around the face.   See below for some thoughts on installing a residential unit in your RV.   Small residential microwaves can be found for under $70, making them fairly inexpensive.

Installing a microwave in an RV that has never had one, is not too difficult but it may require doing some wiring as well as creating an appropriate space in the cabinetry to install it.  You can minimize the wiring problems by choosing a location near an existing outlet.   Even some older RVs that didn't have microwaves may have been pre-wired for one, so search for "hidden" outlets inside kitchen cabinets.  A cabinet with an internal outlet, especially one over the stove, was probably intended to hold an optional microwave.  Ideally you can run wiring inside walls or cabinets to install a new outlet if needed.   If you can't run new wiring inside walls or cabinets you may have to string the power cord from the microwave to an existing outlet.   If there isn't an outlet within reach, you may have to run wiring in surface "tracks" or conduits to install an outlet near your microwave location.  Make sure any wiring you use is of adequate gauge for the input wattage of the microwave. Zip-cord is easy to use, but is not heavy enough to handle the load and you risk an electrical fire or damaging your microwave if the wiring is inadequate.   Worst case, you may have to add a whole new circuit, including a new breaker, to your 120 volt panel (if there is room and available amps).   If you are not familiar with 120 volt wiring practices or are not comfortable doing the wiring yourself, have it done by a qualified RV technician or licensed electrician.   Choose a convenient location for your microwave, usually in an existing kitchen cabinet.   You will need a space that is somewhat larger than the outside dimensions of the microwave so there will be adequate ventilation.  Normal home units are placed on a counter top so they have all round ventilation.  Counter space in most RVs is usually limited, but if you have room to put your microwave on the counter, go right ahead.  Just make sure it is properly secured so it doesn't fall off the counter during routine driving maneuvers. Microwaves that are RV-ready will probably have baffles or air guides to facilitate and redirect ventilation.  If you are adapting a regular residential unit you will need to consider minimum clearances AND provide for adequate air flow to cool the oven.  You may need to install a roof or wall vent to allow hot air to escape.  Your best bet it to buy an RV-ready unit with the trim kit to make installation as easy and safe as possible.  Sometimes the trim kit will come with the unit, sometimes you have to purchase it separately.  If you are using a residential style microwave you may have to create your own trim and/or modify the cabinets to provide a secure mounting and cosmetically pleasing installation.   Remember, your RV will be subject to various kinds of stress on the road and you don't want your microwave to fall out!  Trim kits usually attach to the unit with screws before it is slid into the cabinet, then the face of the trim, which overlaps the opening, is screwed in place to secure the unit.   Lacking a proper trim kit, you may be able to strap the microwave in place securely from side to side using metal straps like plumbers tape or nylon straps.   Then you can fit wood trim around the front for a clean look.   Trim kits usually have vents below and above the front of the microwave to allow for ventilation.   If you don't have adequate ventilation through a roof or wall vent inside the cabinet you may need to provide openings in the front.  Cutting any trim so there is a gap above and below the microwave may be one option.   Drilling holes in the facia might be another. If you have to build your own trim, be sure to monitor the heat inside the cabinet the first few times you use the microwave. It WILL get warm, but the outside of the microwave should NEVER get too hot to touch, which could result in a fire!   If it is getting too warm, find a way to increase the ventilation.  You might have to install an exhaust fan to assist in expelling hot air from the compartment.   Wall and ceiling vents are other possible options but the installation is more difficult as you have to cut holes in the wall or ceiling.   Be sure to install weatherproof vent covers on the outside.  If you need to vent around the front of the microwave, you can probably find some attractive grille material to give it a finished look.

RV rated microwaves are going to give you the longest life and best service.   Units that have been RV rated should have 'hardened' electronics and extra buffering to protect them against the jolts and vibration of travel  as well as properly designed ventilation.

A portable microwave oven is also an option for most any RV or even for tent camping.   Small, lightweight microwave ovens can be purchased for as little as $69 brand new.  If you have room to transport them, you can simply set them up on a convenient table or counter top and plug them in and you're ready to go.   Store them someplace near or on the floor when on the road -- in a cabinet under the dinette seats or even just on the floor under the table.   If you have campground power or a large enough portable generator you can also use them when tent camping or tailgating.  Using a portable microwave avoids any problems of installation in a cabinet with insufficient ventilation.  You will need to find a suitable place to secure the microwave during travel.  For best results, it should also be padded to mitigate some of the possible physical damage from movement and vibration during travel.  Sometimes it is advisable to retain the original carton it came in, complete with styrofoam packing, to protect it during travel.

Happy nuking!