⚠️ Safety Warning: Appliance repair involves electricity, gas, and moving parts. Always disconnect power before working on any appliance.
Error Code: H4 / B4 Difficulty: Hard
Problem: Incorrect wiring.
How to Fix H4 / B4 Error (Step-by-Step)
- Unplug the dryer from the wall outlet to ensure your safety by completely disconnecting the power.
- Remove the top panel of the dryer by unscrewing the screws holding it in place at the back or sides, then slide it off to access the internal components.
- Locate the Main Control Board, typically a larger circuit board with many wire connections, and the User Interface Board, which is situated directly behind the control knob and display panel.
- Carefully examine the bundle of wires (the wiring harness) that connects the two boards. Look for any signs of damage, such as pinched wires, burn marks, or loose-fitting plastic connectors at either end.
- Systematically unplug and then firmly reconnect each wire connector on both the Main Control Board and the User Interface Board. A secure connection is often confirmed by a clicking sound.
- If inspecting and reseating the wires does not resolve the error, one of the boards is likely faulty and needs to be replaced. This is an advanced repair, and caution is advised.
- Turn the appliance off, wait about 2 minutes, then turn it back on.
Parts Availability Note: For this Electrolux/Frigidaire error code, exact OEM part numbers can vary by model revision and serial range. We’ve listed the most likely component(s), but confirm compatibility using your full model number before ordering. If no exact SKU is shown, use this guide for diagnosis first, then verify the matching OEM part on RepairClinic or PartSelect.
Still Not Working?
If the replacement part didn’t fix the issue, you may have a wiring problem or main board failure.
Most DIY parts are $50–$250. If you have a quote, use the total.
More options (for a better recommendation)
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Expert: Mike Sullivan
EPA Section 608 Certified Technician with 18+ years experience.
Read Editorial Standards →Browse all Electrolux error codes: Electrolux Error Codes
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