How to Fix a Frozen Defrost Drain in Your Upright Freezer

Have issues with ice buildup in your upright freezer’s defrost drain? Finding a huge frozen block preventing your freezer from cooling normally? This frustrating freezer malfunction is likely caused by a problem with the defrost drain system.

We’ll cover how the freezer drain and defrost system works, why you may be experiencing a frozen drain, and provide actionable steps to diagnose and fix the issue yourself.

If you find out that you need any replacement parts for your appliance while you’re troubleshooting, you can enter your model number at AppliancePartsPros.com to order them. Most orders arrive in just two business days, and we have thousands of free guides to show you how to install your new parts.

The information in this article may not apply to your specific appliance model. We recommend consulting your manufacturer’s documentation or contact us with any questions.

Freezer drain and defrost system overview

Modern frost-free freezers have a defrost system that prevents ice and frost from accumulating on the cooling coils, known as the evaporator. Ice on the coils would lower the freezer’s efficiency and cooling capability.

The Defrost process

The defrost system includes an electric defrost heater and a control mechanism to initiate defrost cycles. During these cycles, the heater warms the evaporator coils to melt any frost that has built up.

As the ice melts, the water drains away through the defrost drain. This drain is simply a large hole or tube that channels the water out of the freezer compartment.

Drainage typically flows into a pan underneath the refrigerator compartment. Heat from the compressor causes the water to evaporate over time, so it rarely needs to be manually emptied.

Keeping the drain flowing

To keep water moving freely through the defrost drain, a drain strap is attached to the defrost heater. The thin metal strap extends into the drain opening.

When the heater activates, the strap conducts heat into the drain. This prevents ice from building up and blocking drainage.

With this overview of how the defrost and drain systems work, let’s look at what causes freezing issues with the drain itself.

Frozen drain causes

If you notice significant frost or ice accumulation on the freezer’s back wall leading down to the floor, the drain is likely blocked. What causes the freezer drain to freeze up?

Drain tube blockage

One possibility is a physical blockage within the drain tube. Over time, food particles or other debris could collect in the drain, impeding the flow of water.

However, a complete tube blockage is uncommon. The most likely culprit is…

Non-functioning or missing drain strap

Issues with the drain strap are the primary reason freezer drains become frozen shut. The heated strap prevents ice from clogging the drain opening when operating properly.

But the thin metal strap can deteriorate or fall off over time. Without the heat conduction into the drain, ice quickly builds where water tries to exit.

As more water from defrost cycles attempts to drain, it overflows the frozen blockage. Ice keeps accumulating until the entire drain tunnel is a solid chunk of ice.

Replacing a worn-out or missing drain strap is the proper repair in most frozen drain situations. Let’s look at how to diagnose and fix this issue.

Diagnosis and repair

Repairing a frozen refrigerator drain is straightforward when equipped with the right parts. Follow these steps to safely diagnose and fix the problem yourself:

1. Start by shutting off the power to the appliance. Locate the electrical outlet or junction box powering the freezer and unplug it.
2. Turning off electricity prevents electric shock hazards while working on the freezer.
3. The freezer drain and drain strap are located behind a removable access panel on the freezer’s rear wall.
4. Carefully pull the panel straight off the back of the freezer. Set the panel aside in a safe place while you work.
5. With the panel removed, thoroughly inspect the drain opening. Look for a small thin strap of metal extending into the drain tube.
6. If the strap is missing or deteriorated, the drain will require a replacement strap to resolve freezing issues.
7. While inspecting, also check if any debris is clogging the drain tube itself. Use a narrow item like a wire coat hanger to clear any blockages.
8. If the existing drain strap is non-functional, install a replacement part. Locate your model number to look up the correct part. Position the new strap so it runs along the drain opening.
9. Attach it to the defrost heater using the provided hardware. Double-check that it is centered in the drain tunnel.
10. With the repair complete, carefully align the back panel on the freezer. Push it straight on until all edges are flush and the panel is securely attached.

Restore power  

1. Plug the freezer back in and switch the power on. Allow the freezer to run through a full defrost cycle.
2. Monitor the drain tunnel to ensure melting ice water flows out appropriately. No further freezing indicates a successful repair!
3. With a simple drain strap replacement, your freezer drain should now operate as intended. 

Additional information

Thanks for reading! If you have any other appliance repair needs or projects, you can find other resources and our DIY blog at AppliancePartsPros.com. There, you can enter your model number and use our compatibility tool to order the exact parts you need. Most orders arrive in 2-3 business days.

We’re here to help! You can reach our award-winning customer service team at 1-877-477-7278, chat with a pro on our website, and watch thousands of free video tutorials on our YouTube channel.

Make sure to follow us on Facebook, Twitter and Instagram!