Microwave works but does not heat: Causes, 7 Common Problems and Solutions


  • 1 Features self-repair
    • 1.1 Eliminate minor faults: 3 solutions
    • 1.2 Eliminate the serious fault: 4 solutions
  • 2 Output
If microwave oven does not heat up, it is necessary to find the causeIf microwave oven does not heat up, it is necessary to find the cause

Sometimes you may find that serviceable microwave until recently worked but warms up, and we reached a cold dish. The reasons for this are many, and among them there are both serious damage and minor faults can be easily eliminated by hand. Today, let us consider what to do, if not warm microwave and discuss ways to solve the problem.

Features self-repair

Internals microwave ovensInternals microwave ovens

If you notice that the food stays cold even after a few minutes in the oven, it certainly speaks of the device to malfunction. The reason that the microwave turns but does not heat, can be the following:

Photo Description
table_pic_att15087746262 Cause 1

Incorrectly delivered mode. For example, the function "Defrost" can not fully warm up food.

table_pic_att15087746283 Cause 2

Insufficient voltage. Sometimes drops a few volts may affect the work of art.

table_pic_att15087746294 reason 3

Breakage latch on the door and a loose fit it to the oven housing.

table_pic_att15087746315 reason 4

High-voltage fuses, mains transformer or the fuse is blown and must be replaced.

table_pic_att15087746316 reason 5

Failure of the multiplier, which consists of two dependent elements (high-voltage diode and a capacitor).

table_pic_att15087746327 reason 6

Damage to the flow condenser.

table_pic_att15087746338 reason 7

Faulty magnetron and the electromagnetic light.

Careful operation - the key to a long and trouble-free operation of the furnace. Perhaps the reason that the microwave heat ceased, was accidentally hit a metal foil or device chamber. Do not heat food with cutlery in a metal bowl, platter dish with a metallized film and foil containers!

Eliminate minor faults: 3 solutions

Most of the above reasons microwave oven does not heat up, you can fix by yourself, saving considerably on the Service Center. For this we need only a screwdriver and instruments for measuring resistance and voltage.

Ohmmeter - a necessary device for diagnosing faults in a microwave ovenOhmmeter - a necessary device for diagnosing faults in a microwave oven

Instruction and user manual - this is the primary documentation, to which should apply when troubleshooting. Manufacturers often indicates useful information to correctly diagnose problems and possible remedies himself.

Possible lung failure microwave ovens and how to resolve them:

Photo Description
table_pic_att15087746349 Solution 1. wrong mode

Make sure that the control panel is correctly set mode (heating function).

  • With the manual, set the appropriate command.
  • Turn on the oven for 1-2 minutes, after putting to food or a glass of water.
  • Check the temperature of the food, the problem was just incorrect staged mode.
table_pic_att150877463610 Solution 2. undervoltage

The oven does not heat food if a low voltage in your home network:

  • If the outlet is still included with the furnace equipment, then unplug them.
  • Install an uninterruptible power supply, thereby stabilizing the voltage.
table_pic_att150877463611 Solution 3. Faulty door

Often the door in a microwave oven does not close tightly, and sometimes fail latch themselves, which in turn trigger the magnetron.

Decision: replace the latch and shut the door tightly.

Eliminate the serious fault: 4 solutions

In other cases, and if the microwave is buzzing but not warm, it is necessary to address to experts. Repair and replacement of parts under warranty will be free, but in the case of an expired warranty period - for the repairs will have to pay from your pocket.

The price usually includes the cost of new parts and service wizard. But you can save a little, and in this case, replacement of defective parts yourself.

The table below and the visual picture to help cope with the task:

Photo Description
table_pic_att150877463712 Solution 1. Blown (one or more)
  • Unscrew the back cover.
  • Blown fuses immediately separated from the total mass: they are black or swelled.
  • If their appearance is not suspicious, check up resistance.
  • Remove the damaged parts and replace with new ones.

In this case, the microwave oven will be no more problems described above.

table_pic_att150877463913 Solution 2. broken multiplier

You need to check the capacitor multiplier. This will require an ohmmeter:

  • Little resistance to a malfunction.
  • Stationary arrow indicates the absence of contact.
  • A slight deviation or a mark on the sign «∞» indicates normal operation of the condenser.

The failure of this part is often the reason why the microwave does not warm, but it works.

It is worth checking the diode itself. In any case it is easier and cheaper to buy a new part than to fix the old one.

Solution 3. Defective feed-through capacitor EM Lamp
  • Measure the resistance similar to the description above.
  • Tests of the primary winding of the transformer. If it is OK, it should issue a voltage of 220 V. Otherwise, the item must be replaced.
table_pic_att150877464214 Solution 4. Breakage magnetron or electromagnetic lamp

Malfunction of the magnetron may be the reason that the microwave is working - but it does not heat up:

More than half of the defective filament in the magnetron. To remedy the situation, simply measure the resistance to failure diagnosis.

However, it is easier and easier to buy a new magnetron, it is important to write down all the specifications and in any case take with them the old part.

Do not expect cheap devices or microwave little-known manufacturers long and trouble free service. Suppose you spend more, but high-quality branded microwave works for a long time, and in the case of repair - no problem finding replacement parts.


We have examined the most common reasons why the microwave stops to warm up food, but otherwise functions quite regularly. this kind of problem can often be corrected on their own: it is enough just to deal with the instruction in the case of problems to replace the faulty part.

Videos in this article explains and demonstrates possible solutions to problems with microwave ovens. If you have any questions - I will answer them in the comments.

Do not miss the most important:

Once a week we will send the most interesting stuff that you have not seen

We read for 32 to 500 people. Join us!

Food processor dough mixer for home

Food processor dough mixer for homeAppliances

In the household, when preparing food, considerable time is spent on preparatory work: cleaning vegetables for salad and second courses, cutting meat for first or second courses, kneading dough fo...

Read More
Do not repeat these mistakes when buying home appliances: how not to be trapped

Do not repeat these mistakes when buying home appliances: how not to be trappedAppliances

Buying household appliances - an important and responsible task. This category of products is not cheap and is purchased once in many years. Equipment to serve a long time, need to adhere to simple...

Read More
Incredibly cool and unusual devices for the home: useful accessories for creative tea drinking, a bin with the cooling option

Incredibly cool and unusual devices for the home: useful accessories for creative tea drinking, a bin with the cooling optionAppliances

Not all objects invented for home and kitchen become popular and useful. But in most cases, creative solutions find their place, and the housewives can no longer imagine life without them. Thus, k...

Read More