Why would a freezer evaporator ice over?

[Owen Lucas]

Refrigerator temp went down until warning came on. I confirmed the damper was in the open position to allow air to come in from the freezer. I found the freezer evaporator was completely frozen which prevented air circulation.

Defrosted with a heat gun (before unplugging the fridge). Did a defrost cycle fail? What could cause this?

6 year old Frigidaire FFSS2615TP0 side by side.

 

[GSCJR]

Low refrigerant level, or lack of maintenance (dusty/dirty condenser coil).

 

[WobblyElvis]

My 22 year old fridge gave me this problem. It had a timer that would turn on a electric heater under the evaporator coil. The heat would melt the ice and it would drain to a pan under the unit. In my case the heater also had a thermostat that would shut of the heater should get to hot. The thermostat was the problem. In the picture I cannot see a heater element but it may be hidden by the ice.

 

[Owen Lucas]

Low refrigerant level, or lack of maintenance (dusty/dirty condenser coil).

The condenser is the first thing I checked, small amount of dust. No pets, no obstructions. Refrigerant is not serviceable, didn't see any obvious oil leaks. It cools very well now, I just want to avoid this from happening again.

 

[Owen Lucas]

My 22 year old fridge gave me this problem. It had a timer that would turn on a electric heater under the evaporator coil. The heat would melt the ice and it would drain to a pan under the unit. In my case the heater also had a thermostat that would shut of the heater should get to hot. The thermostat was the problem. In the picture I cannot see a heater element but it may be hidden by the ice.

Good point, looking at the parts diagram there is indeed an electric heater. So it could be the heater or timer. If it freezes up again I'll have to diagnose it.

 

[Chris142]

Do these cycle on and off like a car does? If so the thing that makes it cycle is bad and letting it run too long

 

[Reggaemon]

Defrost timer.

 

[WobblyElvis]

Often the electric outlet is hidden behind the appliance. Turning the refrigerator thermostat to off does not remove all electric power. Be careful when working in there.

 

[mk378]

Check the door seals-- excessive humidity entering will overwhelm the defrost system.

This can also be simple operator error not closing a door fully.

 

[eljefino]

My Whirlpool fridge had its coils underneath in a neat pattern that attracted a mink coat's worth of pet hair. Throughout its sordid life in my kitchen I'd occasionally look at the back, covered by cardboard held on with self-tapping screws. "Looks clean", I thought.

It died suddenly so I put all my food in coolers and bought a replacement. Upon trucking it out I found the neglected coils. The new one has coils in the same place. I should get out the vacuum, really should.

 

[joekingcorvette]

I have a six year old Bosch refrigerator and it stopped cooling on Wednesday. I had a certified Bosch repairman diagnose the problem. The tiny electric motor that opens the flap or vent on the top of the refrigerator quit working. It's a very expensive part $250 or more and the tech will come out when the part arrives to repair it. The freezer which is on the bottom works great however the vent on top was closed which didn't allow cold air to cool the refrigerator. The tech put a yellow electric twist wire in there and it keeps the refrigerator at 33 degrees until the part arrive. I would not ever recommend Bosch products. We have a microwave made by Bosch and it needed a new control board after about 3 years and not covered by warranty. Bosch products need a special tech because they are so much different than other appliances. My advice Bosch is very expensive to start and they are not a very good product. They Bosch dishwasher is still working after 6 years.

 

[Rogueman2016s]

Is the fan spinning

 

[snarl]

On mine the electric defrost heater burns out.

 

[bullwinkle]

In order of likelihood:
#1 defrost termination thermostat
#2 defrost timer (should be able to see the clock mechanism moving, generally engages 2-4 times/day)
#3 calrod defrost heating element or wiring

I don't think you're low on refrigerant, since the whole coil is iced up, not just the corner where the cap tube/expansion device attaches. Fan is possible (but would be obvious).

 

[bullwinkle]

I have a six year old Bosch refrigerator and it stopped cooling on Wednesday. I had a certified Bosch repairman diagnose the problem. The tiny electric motor that opens the flap or vent on the top of the refrigerator quit working. It's a very expensive part $250 or more and the tech will come out when the part arrives to repair it. The freezer which is on the bottom works great however the vent on top was closed which didn't allow cold air to cool the refrigerator. The tech put a yellow electric twist wire in there and it keeps the refrigerator at 33 degrees until the part arrive. I would not ever recommend Bosch products. We have a microwave made by Bosch and it needed a new control board after about 3 years and not covered by warranty. Bosch products need a special tech because they are so much different than other appliances. My advice Bosch is very expensive to start and they are not a very good product. They Bosch dishwasher is still working after 6 years.

View attachment 206524

That's a pretty stupid design-the vast majority of refrigerator/freezers have a manual adjustment for that.

 

[John105]

On my 2002, at age 14, this went and the evap iced up.

https://a.co/d/7NhCoN5

I’m now on my 3rd one (obviously they too are not as good as 2002). I also have a spare defrost timer and evap fan, just in case.

Over the years someone said nothing like the evap fan going out and you have to wait 2 days for one and your food spoils. I got a genuine OE Whirlpool on eBay for a discount (like $45).

I’ve tested the resistance of the defrost wire and it’s always been spot on.

I now monitor my temps and look for a temp of the freezer to go up to 15F to 19F, indicated a defrost cycle took place.

The freezer ranges from -5F to +4F. The fridge varies more as it is a function of the freezer and warms as the door is repeatedly opened. Ideally 37F but often closer to 39F.

Interesting Amazon says frequently returned item, but mine works great. I really learned about how my unit cycles etc by observing fridge/freezer temps

https://a.co/d/09rpCht

 

[Owen Lucas]

Is the fan spinning

Yes, I could hear it running and once the ice melted off the airflow resumed.

Interesting Amazon says frequently returned item, but mine works great. I really learned about how my unit cycles etc by observing fridge/freezer temps

https://a.co/d/09rpCht

I just bought one yesterday, easier to monitor the fridge and garage freezer.

 

[B1974]

I also have a Frigidair side by side. If you have a ice dispenser make sure the flapper door on it is closing all the way. I get a bunch of frost when a cube gets stuck in the door.

 

[Warstud]

Upon trucking it out I found the neglected coils. The new one has coils in the same place. I should get out the vacuum, really should.

The Coils on my fridge are on the bottom and theres no way of vacuuming the dirt . I have to blow the dirt out with an air compressor then vacuum up the dirt .

 

[JMJNet]

In order of likelihood:
#1 defrost termination thermostat
#2 defrost timer (should be able to see the clock mechanism moving, generally engages 2-4 times/day)
#3 calrod defrost heating element or wiring

I don't think you're low on refrigerant, since the whole coil is iced up, not just the corner where the cap tube/expansion device attaches. Fan is possible (but would be obvious).

This is it.
Mine was the thermostat, then it was the heating element.
Then the fan blade worn out and I cannot find a replacement so I have to buy a new one.
But it was a 27 years old at that time of replacement.