Refrigerator Frosting Over or Not Cooling? Defrost Heater WP12729128 – Fix Frost Buildup Fast

A refrigerator that frosts over on the evaporator coils, stops cooling, or has water pooling under the crisper drawers is almost always suffering from a failed defrost heater. In Whirlpool-platform bottom-freezer and French door refrigerators, the defrost heater periodically melts frost off the evaporator coils during the automatic defrost cycle — when it fails due to an open circuit, burned-out element, or connector corrosion, frost accumulates until airflow is completely blocked and the refrigerator stops cooling. ⚡ Common failure point across Whirlpool, Maytag, KitchenAid, Amana, Kenmore, and Jenn-Air refrigerators in the WRF, WRB, WRX, WRV, GB2, GX2, MFI, MFT, MFF, MBF, ABB, AFB, KBFS, KBRS, KRFF, and KRMF series. Part WP12729128 is the genuine OEM replacement defrost heater that restores automatic defrost function and directly supersedes 12729128 — no modification required.

Model-specific repair guides: WRF532SMHZ00, WRF532SNHZ00, WRF736SDAM11, WRF757SDHZ00, WRF989SDAB01, WRFA32SMHZ00, WRB322DMBB00, WRX988SIBB00, WRV996FDEM00, GB2FHDXWB00, GX2FHDXVA00, MFI2269FRZ00, MFT2574DEE00, MFT2976AEB00, MFF2258FEZ00, MBF2258FEZ00, MFX2876DRM00, KBFS22EWMS1, KBRS22EVMS1, KRFF302ESS00, KRFF507ESS00, KRMF706ESS00, ABB2224WEB0, AFB2234WEB0, JFX2897DRM00

❓ Is This the Right Part?

This is the correct fix if ALL of the following are true:

• ✔ Your refrigerator powers on and the compressor runs
• ✔ The evaporator fan runs in the freezer (you can hear it when the door is open)
• ✔ The defrost thermostat and defrost timer/control board have been tested and are not the cause
• ✔ The thermal fuse on the defrost circuit is confirmed intact
• ✔ ONLY problem is frost buildup on evaporator coils, fridge not cooling, or water pooling under crisper drawers

Not sure? Send us your model number — we'll confirm before you order.

🔧 Common Symptoms

• Refrigerator not cooling while freezer stays cold — most common complaint
• Heavy frost or ice buildup visible on evaporator coils behind freezer back panel
• Water pooling under crisper drawers or on the floor in front of the fridge
• Evaporator fan running but no cold air reaching the fresh food section
• Refrigerator runs constantly without reaching set temperature
• Defrost cycle error code on digital display

✔ If these symptoms match, the defrost heater is the most likely failed component in the defrost system.

✔ In most cases, replacing the defrost heater with WP12729128 restores automatic defrost and normal cooling immediately.

📦 Part Details

• Part Number: WP12729128
• Type: Genuine OEM Whirlpool-Platform Refrigerator Evaporator Defrost Heater — nichrome resistance wire in glass/ceramic sheath with factory-wired connectors and mounting brackets
• Replaces: OEM direct-fit heater — supersedes 12729128 (no modification required)
• Brands: Whirlpool, Maytag, KitchenAid, Amana, Kenmore, Jenn-Air

⚙️ Installation

Skill Level: MODERATE — Allow 45–60 minutes. Disconnect power before beginning any work. Remove all freezer shelves and bins to access the rear evaporator panel, then remove the panel screws to expose the evaporator coils and heater. Manually defrost any ice buildup with a hair dryer before disconnecting the heater connectors. Transfer the new WP12729128 heater to the same mounting position, reconnect the wiring, and reassemble in reverse. Allow 24 hours for the refrigerator to return to normal operating temperature.

💡 Pro Tip