Thanks for sharing this video! The entire back wall has about a 1.5” thick layer of ice built up. Sometimes I’ve freezes underneath the fan and when it runs it creates a really loud noise. after reading through the comments, I haven’t tried holding the ice maker button to run a manual defrost, but would you think with the amount of ice built up+ the back panel is bent and wrapped pretty severely, that this would indicate a faulty heater? Thanks!
Most likely it’s the heater. Best way to check it is to remove the back panel and check the heater for continuity. If the heater checks out then it could be the defrost termination switch.
I have a sub-zero 700TCI and it seems to be going into defrost mode all the time, (guessing hourly?) I don't know what's normal. Once in a while it will either become to hot or too cold. I reset it a few times and it goes back to set temperatures on the screen. What could the problem be? Last year it was blowing out too hot of air and now it's cooler.
Nice video. I have 700TR refrige and freezer (side by side). Freezer does not go into defrost mode? During summer nonths it freezes up. I have to turn it off for 30 sec. and then it goes into defrost mode and temp comes down. Any help would be fantastic. I dont know if this matters but ice cube maker does not work. It use to work only in winter.
You can check the defrost system by holding in the ice maker button in for 15 seconds until you hear a click, that will force the freezer into a defrost cycle. If the defrost heater comes on and defrosts the coil then I would say you have a problem with the control board. I need more info to assist in your diagnosis.
Thanks for sharing this video - very helpful! My subzero 736TCI is also making noise due to ice build up in the freezer. Checked for continuity on the two heaters (upper and lower) and they both appear fine (30 and 150 ohm reading). Additionally, manually turning the defroster works (ice on/off button for 5 sec). Would you say it is the defrost terminator switch or the control board? Any tips on what I should check next?
If you have 130v at the heater then it’s not the board. Also jump out the defrost terminator when you check, most of the time it’s the Hester. You should check to see how much amps the heater is drawing.
I meant to say 120V at the heater. You can check my website at aaronsrefrigeration.com under technical data to see how many amps the heater draws. Usually around 3.5 amps.
@@SubZeroSpecialists Thanks!! One additional data point - the temperature display is showing 61 for the freezer and 40 for the fridge. That might be the issue (freezer temp recording incorrectly), right? Do we know where the control board is picking the temperature from - is it from the defrost terminator? I'm unsure on where it is - is it visible in this video - if so, can you please point me to it? Appreciate your help.
@@AmitVerma-uf6xx there are two thermistors in the freezer, one attached to the evaporator coil and the senses the cabinet temperature. If your coil is iced up then you’re not going to read the right temps. As a test you could completely defrost the freezer including behind the wall and then turn it back on to see if the temperature normalizes
@@SubZeroSpecialists update: replaced the thermistor in the freezer that was reading the wrong temp (displayed in the freezer temp/control board). Also replaced the terminator switch. The issue is resolved. Thanks again for the video and the guidance!!
My original 700TCI evaporator freezes up. I checked for continuity on the heating element and get 22 ohms. The sealed system seems to hold temps when I manually clear the coil with heat. Since there is no separate defrost controller, my next step would be replace the entire control board? Thanks
There is a defrost termination switch also part of the defrost system, you’ll need to check that also. If it’s open, meaning no continuity, it could be because the freezer evaporator coil is not pulling down enough in temperature to close the contacts. Also if you can apply direct voltage to the heater and see if it heats up or take an amperage reading. If all that checks out then you can check the terminal for the heater on the control board and see if you get 120V. You can also force it into a defrost cycle by holding the Ice Maker button in for 15 seconds. If it goes into a defrost mode then I doubt it’s the board, but I could be wrong.
@@SubZeroSpecialists The original 700tci only has one evaporator. I was able to force a manual defrost via the master power switch cycled off for 10sec. This cleared the ice. I replaced the defrost terminator (inexpensive) just as a precaution. The manual states this early model uses 'adaptive frost' technology since there is no separate defrost controller that was eventually incorporated in subsequent models. So I am not sure what tells the evaporator heater to initiate a defrost in this early model. This was the only reason I was considering changing the board since there is nothing left to change.
@@bcollarguy Adaptivve defrost is based upon how long the heater stays on. You can read about adaptive defrost on our website under tech help, go to 700 series component info.
If you have a meter at the board when you hold ice button for 10 seconds it jumps into a defrost..you can oull the blue wire on the board and check for 120volts coming out of the board at the terminal..put one lead on a white wire and one on the blue terminal on board if you hold ice 5 to 10 second it forces defrost so 120v should come from board...also heater normally is 30 ohms 22 seems low but im not sure
Thanks for the video. I'm not savvy enough to test the voltage of the defroster or any parts, but I handy enough to change the parts. What parts would I need to swap out to be absolutely sure the defrost issue will be fixed? I already removed the freezer panel using your video. The coils with ice are exposed. When I press the ICE button for 5 seconds, the defrost mode kicks in and I can see it working. The question now is which parts should I order online? Without going through testing, I don't mind swapping all the parts related to this issue.
@@tomchong7707 if the heater comes on then you don’t need a heater or a defrost terminator switch. If the ice is built up from the bottom then you might have clogged drain. Completely defrost the freezer and then turn it back on and see if the problem returns.
@@SubZeroSpecialists The drain isn't clogged. This happened 2-3 weeks ago when the service light came on and the freezer wouldn't go below 5 degrees. At that time, I was afraid to remove the back panel. I saw ice building up on the panel itself, so I simply used a hairdryer and the water drained to the pan under the fridge. I thought it was fixed because the temp. reached -3 (my setting). Today, the service light came back. After removing the panel, I can see ice buildup. I appreciate the help here. Thank you!
@@SubZeroSpecialists the surface is snow like, areas between the coils/fins are more ice like and the "curved" part of the evaporator coil has thick ice.
@@tomchong7707 check your drawer seals and the door closers, make sure you’re airtight. Shine a light through the condenser make sure you can see through it. There are two heaters in there, one is down by the drain. You’ll need to know if you’re getting the proper voltage. It’s best to check with a clamp meter which costs $15 on Temu
Continuity in this heatwr should be about 30 ohms. I had a heater had continuity somehow but was 11 and 7 ohm and dancing around but should read 30 ish ohm..
Replace a heater like this it is an adventure
Thanks for sharing this video!
The entire back wall has about a 1.5” thick layer of ice built up. Sometimes I’ve freezes underneath the fan and when it runs it creates a really loud noise.
after reading through the comments, I haven’t tried holding the ice maker button to run a manual defrost, but would you think with the amount of ice built up+ the back panel is bent and wrapped pretty severely, that this would indicate a faulty heater?
Thanks!
Most likely it’s the heater. Best way to check it is to remove the back panel and check the heater for continuity. If the heater checks out then it could be the defrost termination switch.
@@SubZeroSpecialists thank you!
Another Great repair. I like that molex tool where did You get it? It certainly makes for a professional job not having to cut or splice wires.
Waytecwire.com, MX150 & MX150L Terminal Removal Tool
@@SubZeroSpecialists Thanks
I have a sub-zero 700TCI and it seems to be going into defrost mode all the time, (guessing hourly?) I don't know what's normal. Once in a while it will either become to hot or too cold. I reset it a few times and it goes back to set temperatures on the screen. What could the problem be? Last year it was blowing out too hot of air and now it's cooler.
I need more information. What are the operating pressures?
Nice video. I have 700TR refrige and freezer (side by side). Freezer does not go into defrost mode? During summer nonths it freezes up. I have to turn it off for 30 sec. and then it goes into defrost mode and temp comes down. Any help would be fantastic. I dont know if this matters but ice cube maker does not work. It use to work only in winter.
You can check the defrost system by holding in the ice maker button in for 15 seconds until you hear a click, that will force the freezer into a defrost cycle. If the defrost heater comes on and defrosts the coil then I would say you have a problem with the control board. I need more info to assist in your diagnosis.
@@SubZeroSpecialists thank you.....
You can get that thermistor online
Thanks for sharing this video - very helpful! My subzero 736TCI is also making noise due to ice build up in the freezer. Checked for continuity on the two heaters (upper and lower) and they both appear fine (30 and 150 ohm reading). Additionally, manually turning the defroster works (ice on/off button for 5 sec). Would you say it is the defrost terminator switch or the control board? Any tips on what I should check next?
If you have 130v at the heater then it’s not the board. Also jump out the defrost terminator when you check, most of the time it’s the Hester. You should check to see how much amps the heater is drawing.
I meant to say 120V at the heater. You can check my website at aaronsrefrigeration.com under technical data to see how many amps the heater draws. Usually around 3.5 amps.
@@SubZeroSpecialists Thanks!! One additional data point - the temperature display is showing 61 for the freezer and 40 for the fridge. That might be the issue (freezer temp recording incorrectly), right? Do we know where the control board is picking the temperature from - is it from the defrost terminator? I'm unsure on where it is - is it visible in this video - if so, can you please point me to it? Appreciate your help.
@@AmitVerma-uf6xx there are two thermistors in the freezer, one attached to the evaporator coil and the senses the cabinet temperature. If your coil is iced up then you’re not going to read the right temps. As a test you could completely defrost the freezer including behind the wall and then turn it back on to see if the temperature normalizes
@@SubZeroSpecialists update: replaced the thermistor in the freezer that was reading the wrong temp (displayed in the freezer temp/control board). Also replaced the terminator switch. The issue is resolved. Thanks again for the video and the guidance!!
My original 700TCI evaporator freezes up. I checked for continuity on the heating element and get 22 ohms. The sealed system seems to hold temps when I manually clear the coil with heat. Since there is no separate defrost controller, my next step would be replace the entire control board? Thanks
Which evaporator freezer or refrigerator ?
There is a defrost termination switch also part of the defrost system, you’ll need to check that also. If it’s open, meaning no continuity, it could be because the freezer evaporator coil is not pulling down enough in temperature to close the contacts. Also if you can apply direct voltage to the heater and see if it heats up or take an amperage reading. If all that checks out then you can check the terminal for the heater on the control board and see if you get 120V. You can also force it into a defrost cycle by holding the Ice Maker button in for 15 seconds. If it goes into a defrost mode then I doubt it’s the board, but I could be wrong.
@@SubZeroSpecialists The original 700tci only has one evaporator. I was able to force a manual defrost via the master power switch cycled off for 10sec. This cleared the ice. I replaced the defrost terminator (inexpensive) just as a precaution. The manual states this early model uses 'adaptive frost' technology since there is no separate defrost controller that was eventually incorporated in subsequent models. So I am not sure what tells the evaporator heater to initiate a defrost in this early model. This was the only reason I was considering changing the board since there is nothing left to change.
@@bcollarguy Adaptivve defrost is based upon how long the heater stays on. You can read about adaptive defrost on our website under tech help, go to 700 series component info.
If you have a meter at the board when you hold ice button for 10 seconds it jumps into a defrost..you can oull the blue wire on the board and check for 120volts coming out of the board at the terminal..put one lead on a white wire and one on the blue terminal on board if you hold ice 5 to 10 second it forces defrost so 120v should come from board...also heater normally is 30 ohms 22 seems low but im not sure
Thanks for the video. I'm not savvy enough to test the voltage of the defroster or any parts, but I handy enough to change the parts. What parts would I need to swap out to be absolutely sure the defrost issue will be fixed? I already removed the freezer panel using your video. The coils with ice are exposed. When I press the ICE button for 5 seconds, the defrost mode kicks in and I can see it working. The question now is which parts should I order online? Without going through testing, I don't mind swapping all the parts related to this issue.
@@tomchong7707 if the heater comes on then you don’t need a heater or a defrost terminator switch. If the ice is built up from the bottom then you might have clogged drain. Completely defrost the freezer and then turn it back on and see if the problem returns.
@@SubZeroSpecialists The drain isn't clogged. This happened 2-3 weeks ago when the service light came on and the freezer wouldn't go below 5 degrees. At that time, I was afraid to remove the back panel. I saw ice building up on the panel itself, so I simply used a hairdryer and the water drained to the pan under the fridge. I thought it was fixed because the temp. reached -3 (my setting). Today, the service light came back. After removing the panel, I can see ice buildup. I appreciate the help here. Thank you!
@@tomchong7707is it solid ice iron frost like snow?
@@SubZeroSpecialists the surface is snow like, areas between the coils/fins are more ice like and the "curved" part of the evaporator coil has thick ice.
@@tomchong7707 check your drawer seals and the door closers, make sure you’re airtight. Shine a light through the condenser make sure you can see through it. There are two heaters in there, one is down by the drain. You’ll need to know if you’re getting the proper voltage. It’s best to check with a clamp meter which costs $15 on Temu
How did you diagnosed faulty heater?
Check the heater using a continuity meter
Continuity in this heatwr should be about 30 ohms. I had a heater had continuity somehow but was 11 and 7 ohm and dancing around but should read 30 ish ohm..
Electrolux blood storage cabinet,temperature is varying abnormal