RV Microwave Not Working? Here’s How To Fix It

An RV microwave not working can be frustrating, but fortunately it is a relatively simple RV problem to diagnose and fix.  We’ll walk you through the most common RV microwave problems and how to fix them in today’s guide.

RV Microwave Not Working: Common Causes

RV Microwave No Power

RV Microwave Shuts Off During Use

If you have an RV microwave that will run for a little bit then shuts off before the time’s up, you may have a situation that’s causing the microwave to overheat.

Check the venting around the microwave to make sure everything’s installed correctly.

Alternatively, if you recently replaced your RV microwave and the new unit is suddenly shutting off, double check the wattage to ensure it’s not too high.

If the watts are too high on your new RV microwave it may the breaker while running it, causing it to lose power.  

RV Microwave No Power – RV Microwave Not Working & Has No Display

If your RV microwave’s display is blacked out, this usually indicates that there is no power going to it.

Your RV microwave uses a 120V power supply, so if the power is interrupted somewhere, your microwave will not work until this issue is resolved.

While it may seem obvious, check your RV microwave to ensure it’s fully plugged in before trying these next steps.  Often the easiest solution is the first one to attempt.

Also check the outlet itself to make sure power is getting to it by plugging something else in where the microwave was plugged in – if there is power at the outlet, the issue is with the microwave itself and not the power source.

While you’re doing this, go ahead and plug your microwave into a separate outlet that you know works well – if the microwave works properly, then you know the issue is at the outlet.

Check to see if the roof A/C unit is working on your RV.  The AC and microwave both use the same power supply, so if one is working, the other one should as well.  If only the AC works, you can rule out the power supply as the source of your problem.

Take a look at the breakers on your power converter to make sure they’re switched to the ‘on’ position – if they’re not, they won’t deliver power to your microwave.  Even if they’re on, sometimes switching the breaker off and on again could help resolve the problem.

As a last option, check to make sure your coach battery and 120V power supply are working with each other.

If you determine that the issue is with the microwave itself and not the power source, you can attempt to replace the internal fuse of your RV microwave to see if that is the cause of the issue.

Some RV microwave fuses are very easy to get to while others are not.

RV Microwave Lights Up But Doesn’t Heat Food

If the RV microwave’s display and lights are working but it’s not heating food, you can rule out a power supply issue from being the problem.

However, the most likely cause of your RV microwave lighting up but not heating food is that the unit itself may be broken.

At this point you can decide whether or not you want to attempt to diagnose and repair the RV microwave yourself, call a service technician out, or if you’d just rather replace the unit altogether.

Most of the time, replacing the unit is cheaper and faster than trying to fix an existing unit, but that is totally up to you.

Now figuring out what specific part is wrong with your RV microwave is an entirely different issue, as it could be any of the following:

Broken RV Microwave Door Switch

If the door switch (also called an interlock switch) on a microwave is broken, the microwave will act like the door is open even if it’s closed, which will cut off power to the other internal parts and not allow it to heat food.

Test your door switch with a multimeter for continuity, and replace if there is none.

RV Microwave Magnetron Needs Replacement

The magnetron is the part of your RV microwave that produces heat to cook food.

If it’s broken, it could blow a fuse in your microwave which could damage other parts of the appliance.

Test it with a multimeter, and if you do not read 2-3 ohms of resistance then it needs to be replaced.

RV Microwave High Voltage Diode Is Worn Out

Your microwave’s high voltage diode helps power the magnetron, so if it’s out, the microwave isn’t going to heat food.

Again, test with a multimeter to see if you need to swap out your RV microwave’s high voltage diode.

Here’s a great video showing you how to test for these common problems:

RV Microwave Replacement

So you’ve followed the test options above and have ruled out the power source as the culprit for your RV microwave not working.

If the power source isn’t the problem you may need to replace your RV microwave.  Follow the steps in this guide to swap yours out.

How to replace RV Microwave

  • Step 1: Measure your existing RV microwave’s length, width, and height.  Matching your new unit to the same size ensures you won’t have any issues fitting it into your existing cabinetry.
  • Step 2: Take note of the wattage of your old RV microwave.  Buying a new RV microwave with too much power will cause tripped breakers and your microwave won’t work consistently if you get one that needs too many watts.  If you do buy a RV microwave with higher watts, make sure your RV’s electrical system can handle the demand.
  • Step 3: Remove and discard the old RV microwave, keeping any screws that may have come with it in case you need that for special installation on mounting into your cabinets.
  • Step 4: Install your new RV microwave according to the manufacturer’s instructions, paying extra attention to mounting the new unit properly and setting up the venting system per the specifications.

You can watch this quick video that shows how simple the RV microwave installation process is:

Wrapping Up Common RV Microwave Problems & Fixes

We hope this guide helped you to figure out why your RV microwave isn’t working and assisted you in solving the problem.

Let us know any extra tips you have for your fellow RVers in the comments below.

While you’re here, check out our other helpful RV DIY guides for motorhome fuel pump replacement, how to prepare for an RV one night freeze, and how to fix an RV toilet not holding water.

If you’re dealing with an older camper or RV, take a look at our walkthroughs on how to fix a sagging RV slide out and how to fix an RV air conditioner freeze up as well.

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