How To Test A Defrost Heater On A Refrigerator or Freezer
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- เผยแพร่เมื่อ 5 ก.ย. 2024
- If your refrigerator or freezer is not cooling you should check to see if it is going through the automatic defrost cycle. If you find that it is not going through the automatic defrost cycle then you should test the defrost heater. This free video shows step by step instructions on how to test your defrost heating element using a multimeter or ohm meter.
For information on how defrost thermostats work, please see this video: • How To Test Your Defro...
If you find that you have a bad defrost heater you can shop for a new one on our online store by searching with your refrigerator or freezers model number, or entering the part number off of the heating element here: partsdr.com/app... We sell new OEM appliance parts for Whirlpool, Maytag, Kenmore, Amana, Estate, Roper, Frigidaire, Electrolux, Tappan, Westinghouse, Kitchen Aid, Jenn Air, Bosch, LG, Samsung, and more.
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Helped out a lot, thanks! My heater was good, 21 ohms, it was the control board.
Awesome! Thanks for letting us know!
Mine too it reads 29 ohms and thermostat isnt raised up and manual cycling the heater I get nothing so I assume timer is issue
While cleaning out under the fridge I went ahead and measured the amp draw while in defrost mode. Defrost mode causes power to condenser fan and compressor to be suspended for about 30 minutes. The draw of the heater element on mine was 4 amps for about 10-15 minutes. Then it just sat there for another 10-15 minutes with zero draw. At that point compressor and fan kicked back on. Defrost cycle happens every 10 hours of compressor running time and takes about 25-30 minutes to complete
Those results sound perfectly normal! Thanks for sharing!
Thats the video I've been looking for,
👍🏻
Would like you to trace back to check/ replace timer
Excellent!
Good helpful video sir
Great, thanks!
Thanks!
Thanks for the support!
For defrost heater with an attached thermostat (like the one you mentioned at 1:45 in the video), why do you have to cool down the thermostat to closing temperature? Do you suppose to get infinite resistance at room temperature because the thermostat is not closed? If I get about 140 Ohm at room temperature, does that mean the thermostat is stuck closed? Does the resistance suppose to drop when I put the thermostat in icy water?
Check out this video for more information about defrost thermostats here: th-cam.com/video/7kcvlnW8QYo/w-d-xo.html
The defrost thermostat on your refrigerator is probably a safety high limit thermostat with a high closing temperature which would mean that it would have continuity at room temperature.
Could not see the multimeter display clearly. Very dark. Good info.
How hot does the heating element in a freezer defrost system at full capacity ? like mine is rated at 725 watts heater
I've watched probably half a dozen videos related to this topic, and I've heard some various things in relation to CalRod type heaters and recommended resistance ranges. I have a Roper/Whirpool rt18akxkq09, the defrost thermostat has continuity at 0 deg F, so I'm fairly sure it's in good shape. But my heater is testing out at 34.4 ohm. I've heard elsewhere that 200-300 ohm is expected from CalRod type heaters, but here you say anything between 10 and 100 is good. Any advice for me? If it's not the heater, or the defrost thermo, then should I look to the timer in the lower cabinet next or what's a good next step of attack?
Sorry to ask so many questions, I'm really trying to avoid paying out for another fridge, or hiring in to have this repaired. I really appreciate any assistance you might be able to provide!
An easy way to figure out what resistance the heater should be is to find the voltage and wattage rating stamped and laser engraved into the element and input those into an ohms law calculator here: www.ohmslawcalculator.com/ohms-law-calculator. I would guess that your heater is good from the reading you are getting. If all of your defrost components are testing good, then start by replacing the defrost thermostat as sometimes they won't register bad during a test because they can act up intermittently.
Parts Dr So, this was it. I waited a couple weeks just to be sure I didn't have another freeze up incident. 3 weeks in after splicing/soldering in a new defrost thermostat, and no further freeze ups. Definitely does seem like it was the thermostat intermittently failing to cause my issue. Great advice and many, many thanks!!!
Awesome! Glad that fixed the problem for you!
My fridge trips the RCD every 3 or 4 hours but otherwise operates well. Could that be a problem with the defrost heater? I thought it likely but above someone says it only energises every 10 hours?? Any suggestions appreciated
Most refrigerators do not defrost that often, it's usually a minimum of 6 hours but the newer refrigerators vary the length of the cycle using a control board and multiple factors like how often the doors are opened.
Hie there, I'm looking for defrost heater for AEG Santo 78763kg
I know this is an old video.. But thought I would give it a go.
I have troubleshooted my way to either a defrost problem, thermostat/t-couple, or forbid.... A bad board.
Is the general resistance of the element usually always around 50 to 200 Ohm? For home refridgs regardless of model?
My unit (kenmore 106.566) froze up for the first time since bought in 2005. Have not checked the element yet until ice melts. It freezing up worries me, otherwise the compssr, evap fans, baffles, coolant all seem fine. Has to be a defrost problem. Aren't there also one or 2 thermistors/thermo-couples or a thermostat on the defrost assmbly? If testing the therms, is a continuity ok? . Or do the therms have a resistance range also before failure?
I can change these sensors and the element out if I knew the exact points on the failures of the therms or heat element. Assuming the CPU board isn't bad.
Thanks.
We have a video on how to test the defrost thermostat here: th-cam.com/video/i4SNEgPoUMY/w-d-xo.html
The model number that you provided is incomplete.
Yes, most defrost thermostats regardless of model will be around the 50-200 ohm range.
My heater gives me 0.6 ohm...is it bad?
Also i have two wire fuse after the heater which don't give continuity.
I don't know if changing those will solve the problem if I've this value on the heater..any help?
I don't know why there's a thermal fuse before the heater and two electrical fuse after it, I've never seen something similar in any other video
Do you have to remove the defrost heater in order to test it? My fridge is not cold so I left it plugin & unused for at least 4 yrs, now I empty & cleaned it in order to give it away. I find a big chunk of ice covering the evap fan motor, wiring harness, freezer coil down to the bottom tray of the fridge. I broke the ice off to find the fan motor has some rust & some wires broken off. I bought the new evap motor but the wiring harness is not the same. So I bought the used one that comes with the harness & defrost thermostat (exactly match & same OEM part no.), I just need to switch & splice the plugs (for defrost heater) since mine is bigger. The rest is plug & play but the fan attempt to spin for 1 sec & off. I tested the V on the new motor (133V) & on this used one (93V). The seller (eBay) said they tested the fan before they shipped & it works, they also said it attempted to spin & 93V means "It Works". Does this used motor still good (at 93V)? Right now my freezer can freeze the food & my fridge is cold enough to keep the food cold without the working fan. I don't know the temp on the fridge side but I saw a little bit of water on the bottom of the fridge turn into ice. Right now, I guess that it's either the defrost heater or the control board (or the evap motor). How to test the control board? I'm not mechanical or technical incline, I started to watch a lot of TH-cam videos regarding the fridge not being cold. I have Frigidaire side-by-side model: FRS26LF8CS8. I need help & advice. This will save me money not to buy a (good used) fridge. Thank you.
You do not need to remove the defrost heater to test it.
@@PartsDr I unplugged it & I don't get anything. Does it mean my defrost heater is BAD? My defrost heater end is a male, not female plug like most videos that I saw on TH-cam. Is there a way to test the control board?
they really need to have the evaporator coil for freezer and cooler, so no more need for defrost heater, fan, and vent. Any vent ought to be piped outside the refrigerator, through the room temperature, instead of just straight down from freezer to cooler.
Most refrigerator manufacturers offer dual evaporator models on their more expensive model refrigerators.
Hey
Looking for defrost heater for refrigerator Toshiba model (gr-r5ate)
Please advise for the heater model.
Thanks
On the lowest ohm scale I get 106 reading after leaving it in the freezer for 1/2hr and I get 102 after leaving it in a warm oven 100F does that mean my heater is hooped?
That reading most likely indicates a good defrost heater.
Mine is staying at 1. Am I doing it wrong? I have the glass tube type
Can I check the defroster just by just unplugging the clip and turning the fridge off instead of talking it completely off ?
Yes you can. Just make sure the wires are disconnected from the defrost heater.
@@PartsDr Thanks alot my friend I really appreciate the fast response 🙌 🙏
Is 62.2 ohms ok for a Samsung RF4289HARS ver 01 freezer heat element? Seem kind of lover element was frozen by drip pan hole!
That reading sounds good to us! If you haven't already, try testing your temperature sensor on the evaporator coil using the instructions here: th-cam.com/video/J5bwcteeJNM/w-d-xo.html
How to change the defrost heater in a Maytag freezer
We have a video on replacing the freezer defrost heater in a Maytag here: th-cam.com/video/Hqm-4cXfzns/w-d-xo.html
Hi, what about testing when I have an assembly of heater and thermostat, not just heater only? Mine are together so I don't know which one is broken, the heater or the thermostat. Thank you.
You have two options. You can test it as one circuit or cut and splice the wires between the thermostat and heater to test each part separately. They are most likely sold as one part, so even if you narrow down which one is bad, you will still most likely end up replacing both parts.
There is a much easier way than cutting and splicing. Use a probe that is very sharp and just push it in through the wire insulation right into the conductor on the wire coming from the element to the thermostat. Once you've determined that the element is good...30ohms for example....then you can use a really cold ice pack to wrap around the thermostat. Hold probes on both ends of assembly, now including the thermostat, and watch the meter as the thermostat gets colder. If the thermostat is good and your gel ice pack is really cold (from a good freezer), then, once the thermostat reaches its rated closing temp (maybe 20 degrees) you will see the meter instantly go from open circuit to whatever the ohm reading was without the thermostat in the circuit...30 ohms, in this example.
Bro how to test the heater with thermostat
Can i test the volts coming out of inputs to see if the control board is sending power?
Yes you can, but you would need to either make sure the refrigerator is in the defrost cycle or find a way to force your refrigerator into the defrost cycle.
@@PartsDr how can i force into defrost cycle?
@@michaelgreene5525 What is the model number of your refrigerator?
@@PartsDr RF260BEARESR
@@PartsDr oops its RF260BEAESR
Mine defrost heater was burned out. The tube was black. I changed it out. Now everything is fine. I also changed the thermostat.
Nice Job!
I read my heater 410ohms it is good or bad.
What voltage does it operate off of?
is it normal for inside the bulb to turn grayish black like the bottom one at 2:03?
It is normal for the glass tube defrost heaters to discolor like this over time.
What if my thermostat and defrost heater test good ? What else can cause the the heater not turn on, pcm ?
Most older refrigerators had 3 defrost components. Defrost timer, defrost heater, and defrost thermostat. Most newer refrigerators have 4 defrost components. Defrost heater, defrost thermostat (high limit safety), defrost sensor (thermistor), and control board.
I know you said you test all heaters the same. Just confirming that goes for the aluminum one right?
Yes that is correct. Inside of the aluminum tube is a heater, so it gets tested the same way.
Hello,
We have an Ariston hotpoint SDS 1721 V/HA fridge that makes too much ice on the back panel. We've changed the thermostat, but there's always too much ice. Could you tell us what kind of problem there could be, and where is the defrost heater on that kind of model. It could also be a command card problem... Thanks in advance for your answer (We're writing you from France).
I'm sorry, we do not have any information on this model since it is an international model refrigerator.
if its has infinite reading. what will that mean?
I have a maytag MSD2554DRA that is kicking out a GFI outlet but it only does it after a number of hours. Could the defrost heater be the cause? There is no thermostat setting for the defrost heater . When plugged into a non GFI circuit it works ok so there must be a surge from the refrigerator causing it.
Yes a bad defrost heater or defrost thermostat can cause the refrigerator to trip the GFCI outlet.
@@PartsDr Thanks, I'm going to look at it since it seems like the likely suspect since it takes hours for it to happen.
Hi Ryan, Thanks for this wonderful video. For SAMSUNG DA 47-00244u-00, what should be resistance reading at room temperature for a good defrost heater. My shows 140 ohms. Is my heater good ?
That reading would indicate that the defrost heater is good.
Thanks very much !
The refrigerator defrost heater in our Samsung refrigerator (RF28HFEDB...) has an integrated inline fuse. Testing across the whole assembly (heater + fuse) from one connector to the other produces 147 ohms. I would assume that both heater and fuse are good? True? If so, the evaporator's both sensors and fan are testing OK. Suggestions for other cause for ice build-up in the top of the evaporator coil would be greatly appreciated. Thx.
It sounds like the heater and bimetal are most likely good. The next thing to check is the defrost temperature sensor. We have a video on temp sensor testing here: th-cam.com/video/J5bwcteeJNM/w-d-xo.html
The defrost heater and thermostat test fine, but the coil defrost cycle isn't happening. What's the next suspect?
What is the model number of the refrigerator? partsdr.com/model-number-locator/refrigerator
@@PartsDr LFFH21F7HWJ
@@davidmaschke8801 There should be three defrost components on this model, the defrost heater, defrost thermostat, and control board. If the thermostat and heater are good then it is most likely the control board that is bad. Although we do recommend replacing the defrost thermostat anytime you have a defrost issue as sometimes they will bench test good but act up and fail when installed in the freezer.
So, 1.2 ohms is bad?
Okay, there are wires on both ends. The other end shows 104.8 ohms.
Maybe it's the temperature sensor? That shows nothing happening. OL
We would probably need to see a picture of what you have.
I get a notice when someone like something I chatted. Not when someone replies. I need to figure out the settings. But I don't know how to post a picture, other than make a video of the pictures I have, to upload to yt. But after I posted that, I found out the multimeter I was using sucked. When I got my new one and tested it, it was good. I'm starting to get the bottom drawer stuck now, and it will not roll/pull out. So I will need to thaw it out again. I made a new piece that goes from the heater to the drain, that looks similar to the new replacement version of it. I noticed the next day, after I fixed it, a crack at the back of the fridge was already freezing moisture at the back of it.
How hot can a defrost heater be? Max temperature
They do not rate a max temperature for the defrost heater itself. The temperature of the heater is determine by the voltage and wattage rating. Most refrigerators will limit the temperature of the defrost heater with the defrost thermostat or defrost thermistor & main control board. You will want to check the schematic for your model refrigerator for more information regarding that.
@@PartsDr Thank you for reply. I found some site explaining how temp is calculated. Thanks again.
My old heater was reading 173 ohm. The brand new part I bought is reading 165 ohm. Seems way too high do you think?
According to the math that would equal around 83-87 watts if your refrigerator using 120v AC power. That is most likely correct and a good heater from our experience.
Parts Dr Thanks for your reply. My fridge is 240v AC 50hz. Is that still okay?
@@pufffdragon Yes
Parts Dr Great! Thank you. Also thanks for the very informative video. Glad I found you.
I followed this video to test a defrost heater i thought was having a problem and a brand new one - thinking I had to change out the old one. The continuity reading came out the same more or less. Am I doing something wrong? The Ohm value was well under 1.0. It was in the tenths and hundredths places of the decimal. The multimeter was set on the ohm symbol that says 2k
Try using a lower setting on the multimeter, you will want to use the 200 setting.
Is good 110 ohms?
Yes most likely
@@f1livenews2023 That sounds like a good reading. That is probably operating off of 220v.
Hi, i didn't get a reading at all when touching the two heating terminals, but got one of 81.5 when I touched both volt meter ends to the same heating terminal, what does that mean please?
It means that’s funny
@@gaildimick1831 yeah, it needed replacing in the end!
mine got 50.7ohms.
That is most likely a good reading
mine read 43 ???
That sounds like a good reading
I don't buy the comment "continuity test will not work on some defrost heaters because the ohm value is too high.....". A heater element, by design, needs to draw enough current to make heat...which means the resistance has to be low enough to create heat....under 100 ohms is typical....at 115VAC that's about 1 amp of current....if the ohm value is "too high" for a meter to measure, then the resistance is way too high to create any heat (current) at all...it's simple ohms law. A good heater with an 'ohm value too high' does not exist.
You are wrong. It is common for the refrigerator section defrost heater on newer models to use a lower wattage heater. 120v and 120w is common and that is 120 ohms which is above the continuity range for most multi-meters. Also, continuity is multi-meter brand specific, some multi-meters won't register continuity if it is over 50 ohms.
@@PartsDr Yes, lower wattage heaters are out there, I just replaced one in mine, but "120 ohms is above the range for MOST multi-meters"?? That is simply not true, and if you can back that up with the name and model of more than one meter that doesn't have the range or capability to measure 120 lousy ohms, I'd be surprised. That meter has ONE range, and it's maybe 100 ohms??? There may be some really really low end meters that are simple continuity testers but they are not multimeters. I think anyone who is going to be a DYI person to attempt this troubleshooting, will have spent more than $25 on a multimeter, which is piece of crap, but will easily read 120 ohms.
@@elguapo5467 Klein Tools 600V from Home Depot. Continuity Check: Audible signal
@@PartsDr From specs in description: "Multimeter measures up to 600V AC/DC voltage, 10A AC/DC current and 40 MOhms resistance". That means this meter can measure up to 40 MEG ohms, and I don't think you've ever had a defrost heater that had a resistance more than 40,000,000 ohms. But what do I know?
@@elguapo5467 Yes it can measure the resistance, but it won't register continuity 50 Ohms or higher.
Useless