Free Shipping $49+
Factory Direct No Middleman
30-Day Returns
24/7 1-800-HEIMA-00
Excessive frost accumulates on evaporator coils because the board fails to trigger the defrost heater at correct intervals, blocking airflow and reducing cooling.
Fridge compartment rises above safe temperature while freezer seems fine — caused by ice-blocked evaporator coils due to missed defrost cycles.
The unit never cycles off because the defrost control board is stuck and cannot alternate between the cooling and defrost cycles properly.
A power surge or continuous wear can cause the defrost control board to fail completely, preventing the refrigerator from starting.
Erratic temperature swings in the freezer due to the board failing to regulate defrost cycle timing and heater activation correctly.
💡 Pro Tip: Diagnosing a Faulty Defrost Control Board
Your part is likely the culprit if you notice any of the following:
⚠️ Excessive frost or ice buildup on the evaporator coils in the freezer compartment
⚠️ Refrigerator section too warm while freezer appears normal
⚠️ Compressor runs continuously without cycling off
⚠️ Refrigerator not running at all after a power surge or outage
🛠️ Before replacing the board, test the defrost heater (WP2263749) and defrost thermostat (WP4387490) with a multimeter — they should show continuity when cold. If both check out, the adaptive defrost control board 4388931 is your next replacement. You can also initiate a forced defrost cycle by toggling the thermostat Off for 15 sec → On for 5 sec, repeat twice, then back to Off — the board will run a 21-minute defrost cycle.
📦 What's in the Box
✅ 1× Adaptive Defrost Control Board (approx. 3"L × 2.5"W, 6-terminal)
✅ 1× Connector Block
✅ 1× Installation Instruction Sheet
We typically respond within 1 business day. Include your appliance model number for the fastest answer.
Disclaimer: Compatibility information, part numbers, and model fitment data on this page are sourced from manufacturer databases and third-party references. While we strive for accuracy, please verify your appliance model number before ordering. Heima is not responsible for errors or omissions in compatibility listings.
Reviews
There are no reviews yet.