Dacor Microwave DMW2420S

[diamondrichlb]

I have a Dacor DMW2420S installed in 2015. It seems to be losing power. Does that even happen to a micro or does it just die? As an example, it has a auto cook cycle for baked potato. This worked fine when it was new. A while back the potato started needing an extra Easy Minute. Now it seems 2 Easy Minutes are required to make the potato tender. 

Is the problem the potato or the micro?

Is there a test cycle to tell if the unit is failing?

[johntech]

Dacor's sensor is a semi-conductor device that detects the

vapor(moisture and humidity) emitted from the food as

it heats.The sensor aadjusts the cooking times and power

levels for various foods and quantities.

If it is only acting up in the sensor cooking but works in the timed cooking then I would suspect the humidity sensor. 

Most microwaves have a power output test that has you heat a measured amount of water for a specific time and record the temps before and afterwards. I do not have that info for this microwave nor the specs for the sensor.  Maby someone else on this site will. You can however grab a couple bags of microwave popcorn and test one on timed cook and one on sensor cook.

Part number: 105419

They do have an option to set the sensor cooking for more or less time on page 20 of the owners manual. If you do not have one just google dacor DMW2420S owners manual.

[johntech]

There is a chance that nothing is wrong at all. In the summer time everyone has there air conditioners on which draws more power from the grid lowering the potential at the outlet  which in turn will lower the wattage of the microwave. Also the size of the potatoes will matter. I went on a call where popcorn was burning in sensor cook. When I went thru the manual it stated that it needed to be a 6oz bag of popcorn and his popcorn manufacture had recently reduced there bags to 4oz. He switched to a larger bag and it worked fine again.  

[diamondrichlb]

8 hours ago, johntech said:

Dacor's sensor is a semi-conductor device that detects the

vapor(moisture and humidity) emitted from the food as

it heats.The sensor aadjusts the cooking times and power

levels for various foods and quantities.

If it is only acting up in the sensor cooking but works in the timed cooking then I would suspect the humidity sensor. 

Most microwaves have a power output test that has you heat a measured amount of water for a specific time and record the temps before and afterwards. I do not have that info for this microwave nor the specs for the sensor.  Maby someone else on this site will. You can however grab a couple bags of microwave popcorn and test one on timed cook and one on sensor cook.

Part number: 105419

They do have an option to set the sensor cooking for more or less time on page 20 of the owners manual. If you do not have one just google dacor DMW2420S owners manual.

Thank you, I have the service manual and i found the water heating test which seems pretty broad, but it is what it is. I also found the Add Time option when you do sensor cooking. I'll try both.

[diamondrichlb]

8 hours ago, johntech said:

There is a chance that nothing is wrong at all. In the summer time everyone has there air conditioners on which draws more power from the grid lowering the potential at the outlet  which in turn will lower the wattage of the microwave. Also the size of the potatoes will matter. I went on a call where popcorn was burning in sensor cook. When I went thru the manual it stated that it needed to be a 6oz bag of popcorn and his popcorn manufacture had recently reduced there bags to 4oz. He switched to a larger bag and it worked fine again.  

I had not thought of the reduced power possibility. We live in a 40 story condo in Hawaii so the A/C is running all the time except during winter, but I can see how that might make a difference. As to the size of potato, I did not weigh them so just using the ole eye ball method to determine if the size is close to the same as a year ago and along the time line. That doesn't seem to be the issue, but can't guarantee it.

[Hiroshi]

Power testing can be done on any microwave... if you follow these steps and the result doesn't match your wattage, meter your outlet voltage, and start watching for small details like Johntech described as they may be adding up to what will appear to be a problem in a microwave with no broken parts.

Procedure Using Fahrenheit Thermometer:

1. Pour exactly 1000 milliliters (mL) of cool tap water into a microwave-safe container. Using the thermometer, stir the water for about 10 seconds, then measure and record the temperature. For accurate results the initial water temperature should be between 60 degrees F (15.6 degrees C) and 80 degrees F (26.7 C).
2. Place the container on the center of the oven cooking shelf. DO NOT leave the thermometer in the container. The cooking shelf (tray) or turntable must be in place and any metal racks must be removed.
3. Heat the water for 33 seconds at full power. Use an accurate digital timer or stop watch if the oven has a mechanical timer.
4. After the heating time is completed, immediately remove the container, stir the water for about 10 seconds, re-measure and record the temperature of the heated water.
5. Subtract the starting water temperature (step 1) from the ending water temperature (step 4) to obtain the temperature rise.
6. To determine the output power in watts, multiply the total temperature rise by a factor of 100.
7. Example:
   1. Starting temperature (T1) = 60 deg F
   2. Ending temperature (T2) = 72 deg F
   3. Subtract T1 from T2: 72 - 60 = 12 (temperature rise)
   4. Multiply temperature rise by 100: 12 x 100 = 1200 watts
8. The test may be repeated to insure accuracy

[johntech]

I would meter the outlet and see what the voltage is. Test the power output per Hiroshi's test. You could also purchase a kill-a-watt for around $20.00 to get the actual wattage. 

[diamondrichlb]

I just ordered a Kill-a-Watt on Amazon. Seems like a good thing to have.

[diamondrichlb]

3 hours ago, Hiroshi said:

Power testing can be done on any microwave... if you follow these steps and the result doesn't match your wattage, meter your outlet voltage, and start watching for small details like Johntech described as they may be adding up to what will appear to be a problem in a microwave with no broken parts.

Procedure Using Fahrenheit Thermometer:

1. Pour exactly 1000 milliliters (mL) of cool tap water into a microwave-safe container. Using the thermometer, stir the water for about 10 seconds, then measure and record the temperature. For accurate results the initial water temperature should be between 60 degrees F (15.6 degrees C) and 80 degrees F (26.7 C).
2. Place the container on the center of the oven cooking shelf. DO NOT leave the thermometer in the container. The cooking shelf (tray) or turntable must be in place and any metal racks must be removed.
3. Heat the water for 33 seconds at full power. Use an accurate digital timer or stop watch if the oven has a mechanical timer.
4. After the heating time is completed, immediately remove the container, stir the water for about 10 seconds, re-measure and record the temperature of the heated water.
5. Subtract the starting water temperature (step 1) from the ending water temperature (step 4) to obtain the temperature rise.
6. To determine the output power in watts, multiply the total temperature rise by a factor of 100.
7. Example:
   1. Starting temperature (T1) = 60 deg F
   2. Ending temperature (T2) = 72 deg F
   3. Subtract T1 from T2: 72 - 60 = 12 (temperature rise)
   4. Multiply temperature rise by 100: 12 x 100 = 1200 watts
8. The test may be repeated to insure accuracy

I like it, I don't think I have a thermometer. I use a laser for my chocolate or frying oil, but I don't think it's accurate for water. I seem to remember reading that somewhere. Have to get a thermometer.

[diamondrichlb]

I found a thermometer and ran the test 6 times. The temp rise is between 10 to 11 degrees. Sometimes 10 sometimes 11. So according to the formula, all things being equal, best case, the micro is putting out 1100 watts. The micro is supposed to be 1200 Watt. Is 1100 within the realm of acceptable performance or is it indicative of pending failure? And/or could a low voltage supply be a possible cause of less than optimum performance? All other appliances and electronic devices seem to be operating normally, although that is probably difficult to measure from just normal usage.  The Golf Channel and Real Madrid soccer is looking good.  

On another note, the Dacor warranty on this sucks. One year parts only. Is that a normal industry standard? So, from day one if the micro fails I pay for labor. Hmmm....

I was looking a little more closely as it's coming up on 2 years in about 3 months and the CC extended warranty is going to run out. If I want to recover any repair costs I have to submit it in the not too distant future.

[Hiroshi]

was it a digital thermometer? does it read 98.6 if you check your own temp?

[diamondrichlb]

Hmmm.....no, so it could have been 82.6 to 94.4 instead of the 83 - 94 I used - which would be 1180 which is very close to 1200 watts. As it was, most of my measurements were 10 degrees. I rounded up to 11 because of the lack of digits. I suppose it could be that the 11 would round up very close to 12.

[Hiroshi]

Yeeessss, so keep an eye on it and it may save you some headaches, last thing you want to do is make a warranty rquest and get slammed with a bill because the tech can't prove anything is wrong!

[diamondrichlb]

I don't know what's going on with appliance companies these days, but Dacor just gave us an extended parts and labor warranty and scheduled service for our micro. First Subzero Wolf  with our gas range and now Dacor with our micro. I like it. 

[Hiroshi]

Usually, if you call them and inquire, they will extend your warranty if you use their Authorized Service company. Sub-Zero is a goos outfit, it is cool to know Dacor did that for you!

Please let us know if they find anything interesting?

Edited June 22, 2017 by Hiroshi

[AccApp]

Try baking a potato in a conventional oven and compare it with a microwaffen baked one. Well worth the extra hour or so. Better yet, try removing the microwaffen entirely and replace it with something less harmful to yourself and others.

[diamondrichlb]

Certainly something to think about. Thanks for the input.

 

[diamondrichlb]

On 6/21/2017 at 0:12 PM, johntech said:

I would meter the outlet and see what the voltage is. Test the power output per Hiroshi's test. You could also purchase a kill-a-watt for around $20.00 to get the actual wattage. 

Got the Kill-a-Watt. The voltage varies from 118.3 to 117.6. I seem to remember seeing there is a 6% variance allowed when an appliance is rated at 120V? What voltage would make a difference in the output of the micro?

[johntech]

That should not be enough to noticeably effect the output. I crunched the number with ohms law and 120v @ 10 amps gives you 1200w, if that drops to 117.6v  at 10amps you are still cooking with 1176w and at 118.3v at 10 amps you will have 1183w. Now that is just plugging in the known values which are voltage and the microwave wattage rating. 

[diamondrichlb]

Thank you. We have a tech coming out on Friday, supposed to be yesterday, but he got delayed. Sounds like the sensor might be the problem as Johntech suggested.