Frost Build Up In Freezer? Ice Forming? 4 causes and How to fix it

If you see ice or frost build up in freezer, then you might have an issue with the drain line or with defrost system of your refrigerator.

Ice forming in the freezer and frost build up in freezer has completely different causes.

Ice forming in the freezer related with drain line issue, but frost build-up related with malfunctioned defrost system.

In this article we will we show you the difference between them and how to fix it.

Let’s start with ice forming at the bottom and then continue with frost build-up in the freezer.

Ice Forming At The Bottom Of The Freezer

Drain line clogged

Unfortunately, there will likely come a time that you find that there is a build-up of ice on the bottom of the freezer.

Since the interior temperature of the freezer section of the refrigerator is supposed to be maintained at or below zero degrees any amount of water that is inside the freezer area will freeze solid at some point.

One of the more likely causes of water entering the freezer is that the drain that is designed to eliminate any of the condensations from the cooling coils has a clogged grommet.

In order to investigate the cause of ice build-up in the freezer is caused by a clogged drain grommet is not an easy or quick process.

Just couple years ago Whirlpool came up with idea to use a different design of the drain system, which is proven to be more reliable.

So don’t use old (original) design on above, use new design (see pic below). You can get this part here.

How to Fix it?

You will need a couple of tools in order to gain access to the drain for the cooling coil; a screwdriver and ¼” nut driver will do the trick (to see the video how to do it, just scroll down)

A word of caution, you will need to be ready to contort your body into the tight freezer compartment in order to remove many of the screws that are holding the drawer rail system that is inside the freezer compartment.

The first thing you will want to do is unplug the unit and disconnect the water hose from the back of the refrigerator.

Pull the refrigerator away from the wall so that you will be able to get at the back access cover.

To get started you will need to remove the screws that hold the drawer in place using a nut driver.

You will set the door aside and remove the basket from the railing.

Using a screwdriver to pop the two tabs that are holding the wire drawer in the bracket on.

Then remove the two ¼” screws on the end of the bracket on each side and remove wire rack and set it aside.

The next thing that needs to be removed is the ice maker and depending on the model you simply remove all of the screws holding it in place and disconnect the wire and remove it.

Now you need to remove the back access panel to get at the drain.

There is a vent that needs to be removed first and that is held in by a couple of tabs that you pop using a screwdriver.

You will also need to remove the thermistor cover that is also held in by tabs, pop them out of place with a screwdriver and remove it.

Remove the two r screws and remove the back cover.

Once the back cover is removed you see that the drain pain is likely filled with ice and causing the water to leak into the freezer area.

Using a screwdriver to break up the ice and also remove the layer of ice on the bottom of the freezer.

It is now time to replace the drain grommet with a new and larger size one.

To replace it you will need to gain access to the back of the refrigerator and remove the access panel by removing all of the ¼” screws.

Once you have the cover off you will need to reach inside near the middle of the unit for the rubber grommet that is attached to the drain line.

Work the old grommet loose and pull it out since it will be replaced.

The old one will likely be clogged or kind of sticking together which is what prevents the water from flowing easily out the drain.

Pull the new grommet out of the package and pop it back in place.

Once it is back in place you can put the back cover back in place and tighten all of the screws that you removed.

Go back to the front of the refrigerator and put all of the covers back in their place that you removed inside the freezer.

Hook up the ice maker and put the screws back in place.

Slide the drawers back in place and put the screws holding them in the brackets.

Put the basket back in their place that you removed and put the door back on and tighten all of the screws.

Make sure you hook up the water line and plug in the power cord.

Ice Maker water line leaking or overfilling

While having an automatic icemaker inside the freezer compartment is a convenience that most homeowners appreciate.

No need to worry about filling ice cube trays constantly to have enough ice for the family.

Unfortunately, there may come a time that the convenience may turn into a problem if something goes wrong.

One of those problems that could pop up is a water leak that ends up causing some ice to buildup on the bottom of the freezer compartment.

Since the internal temperature of the freezer compartment inside your refrigerator is normally zero degrees and if you have a water leak and it pools on the bottom of the freezer it will not be long before you end up with a thick layer of ice.

There are a couple of things involving the ice maker that can cause there to be water pooling at the bottom of the freezer;

Water pressure is too low for the water inlet valve and it allows an excessive amount of water to flow into the ice maker which will overfill the ice tray and cause a leak.

The other possibility is that there is some type of water leak from the water line for the automatic ice maker.

The water inlet valve for the automatic ice maker that is built-in to the freezer compartment requires that the water pressure be at least 20 psi.

If the water pressure is not high enough the water inlet valve will not completely close.

This will allow water to continue to flow into the ice maker and it will overfill the cube tray.

The additional water will collect at the bottom of the freezer compartment. 

In order to test that there is an adequate amount of water pressure (at least 20 psI) for the water inlet valve to operate optimally, you will need to access the back of the refrigerator.

The best way to test if there is an adequate amount of water pressure for the water inlet valve to operate effectively is to check the stream of water that comes out of the water tubing that is going into the refrigerator.

Without having any tools for testing the actual water pressure you can use a simple test that only takes a minute to run.

The flow of water coming from the hose should be roughly 13 ounces of water per minute.

So a simple test would be to use a measuring cup and see how much water goes into the cup in a minute’s time.

As long as it is 13 ounces or more you don’t have a water pressure problem.

So, find where the water tubing goes into the back of the refrigerator.

Be sure you turn the water valve off that feeds the refrigerator or you will have a big mess when you disconnect it.

Make sure that you have your measuring cup and a stopwatch so that you can time the water going into the cup.

After disconnecting the hose and putting it in the measuring cup turn the water valve back on and observe the water flowing in.

After waiting for the minute look at the amount of water that is in it and as long as it is more than 13 ounces you don’t have a problem with the water pressure.

So, now let’s talk about frost build up in the freezer

Most common reason for that is malfunctioned defrost system. There are several components which may involved into this issue.

Defrost thermostat failed

Defrost thermostat is a device which help to prevent overheating around cooling or evaporator coils.

Thermostat works in series with defrost heater and in case of overheating it will cut power to the heating element.

You need to check thermostat for continuity once it cold, using multimeter.

If you want to check continuity with room temperature, it will show you zero reading, because thermostat internal bi-metal plate will be disconnected. You can read about it here.

Defrost heater burnt out

This is actually not very common for the heater to burnt out, most likely thermostat will fail then heater.

Purpose of the heater to thaw all frost or ice which may build up on the evaporator coils, once fridge will go to the defrost cycle.

You can check continuity of the heating element to make sure its not burnt out.

Control board failed – “Jazz Board”

Some of the Whirlpool, Maytag and Amana Refrigerators come with the specific control board, its called “JAZZ BOARD” .

This board have known to fail very often, by not to initiating defrost cycle.

Causing compressor work non stop and causing a thick layer of frost build up on the evaporator coils.

And here is a video how to fix it.

Damaged or Worn Door Seal

Here is another problem when you might have a frost forming in the freezer.

Close the door and check door seal all around perimeter to make sure there is no gap, where the air may get in to the freezer.

if it is gap, you need to replace door seal with a new one. You can get one here.