Refrigerator Leaking Water Under the Crisper Drawers, Ice Ball Under the Evaporator, or Drain Line Frozen Solid? The Drain Heater Is the Fix.

The refrigerator drain heater wraps around or sits in the defrost drain tube at the base of the evaporator compartment. Its job is to keep the drain tube clear during and after each defrost cycle so that meltwater flows freely into the drain pan below. When the heater fails, the drain tube freezes solid — meltwater from the defrost cycle has nowhere to go and backs up, forming a large ice mass (the “ice ball”) under the evaporator cover. As the ice melts between defrost cycles, water overflows into the fresh food compartment and pools under the crisper drawers or leaks onto the floor. The 502XP (also sold as SH502) is a universal replacement drain heater that fits most refrigerators and freezers with a drain tube heater, restoring proper defrost drainage and eliminating the ice ball.

Symptoms of a Failed Refrigerator Drain Heater

• Water pooling under the crisper drawers or at the bottom of the fresh food compartment
• Water leaking from the refrigerator onto the floor
• Large ice mass (“ice ball”) forming under the evaporator cover or at the bottom of the freezer
• Drain tube frozen solid — confirmed by pouring warm water into the drain and watching it back up
• Refrigerator not cooling properly — ice buildup blocking airflow from the evaporator
• Frost or ice accumulating on the back wall of the freezer compartment
• Gurgling or dripping sounds inside the refrigerator during or after defrost cycles
• Problem recurs every few weeks after manually defrosting the drain — heater is not preventing refreeze

Part Details

• Part Number: 502XP (also sold as SH502)
• Brand: (aftermarket universal replacement)
• Type: Refrigerator Defrost Drain Tube Heater
• Fit: Universal — fits most refrigerators and freezers with a drain tube heater (verify drain tube diameter and routing before ordering)
• Temperature Rating: −50°C to +125°C
• Safety: Internal fuse for overtemperature protection
• Function: Heats the defrost drain tube during and after defrost cycles to prevent meltwater from refreezing and blocking the drain

Installation Notes

• Skill Level: Intermediate — requires evaporator cover removal to access the drain tube
• Unplug the refrigerator before starting
• Remove all food and shelving from the freezer compartment to access the rear evaporator cover
• Remove the evaporator cover screws and carefully lift the cover — the defrost heater wires may be clipped to the cover
• Locate the drain tube at the base of the evaporator — clear any ice blockage before proceeding (see Pro Tip above)
• Wrap or insert the 502XP heater around the drain tube per the included instructions — ensure the heater element is in full contact with the tube
• Route the heater wiring to the nearest defrost heater connection or splice point per the installation guide
• Reinstall the evaporator cover, restore power, and monitor over the next 24–48 hours to confirm the drain remains clear after defrost cycles

Compatible Applications

Universal fit for most refrigerators and freezers with a defrost drain tube heater — including GE, Whirlpool, Maytag, Frigidaire, Samsung, LG, KitchenAid, Kenmore, and others. Verify drain tube diameter and heater routing against your model before ordering. Contact us with your model number if you need fitment confirmation.

✓ Model-Specific Repair Pages