Frigidaire · Washer Serious

E5B — Motor Control Heat Sink Over-Temperature

E5B means the motor control unit (MCU) detected high temperature on its heat sink — an over-temperature fault, not low DC bus voltage.

Keep using it?
Limited use only
DIY difficulty
Hard

How to fix it

  1. Let the washer sit powered off for 30-60 minutes to cool, then retry a cycle.
  2. Check that the area around the washer and the MCU's ventilation isn't blocked or enclosed.
  3. If the model has an MCU cooling fan, confirm it's running.
  4. If overheating recurs with normal loads and clear ventilation, the MCU itself may be failing — replace it.

Why it happens

Typical signs: E5B during or shortly after motor operation (wash agitation or spin) · Washer stops mid-cycle · May need to cool down before it will restart

  • Restricted airflow around the MCU Blocked ventilation or an enclosed/hot installation location keeps the heat sink from dissipating heat.
  • Failing MCU cooling fan (if equipped) On models with a cooling fan for the MCU, a failed fan lets the heat sink run hot.
  • Failing motor control unit A degrading MCU can trip a genuine or false over-temperature fault.

Parts you may need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

  • Frigidaire washer motor control unit (MCU) Common replacement
    Amazon →

More Frigidaire washer codes

E10 E10 — Water fill problem E11 E11 — Fill time too long E13 E13 — Water leak or air leak in pressure system E20 E20 — Drain pump won't pump out E21 E21 — Slow drain / water remains in tub E23 E23 — Drain pump relay fault on control board

All Frigidaire codes → All washer codes →

Frequently asked questions

What does the E5B code mean on a Frigidaire washer?

E5B means the motor control unit (MCU) detected high temperature on its heat sink — an over-temperature fault, not low DC bus voltage.

What causes the E5B code on a Frigidaire washer?

Restricted airflow around the MCU: Blocked ventilation or an enclosed/hot installation location keeps the heat sink from dissipating heat. Failing MCU cooling fan (if equipped): On models with a cooling fan for the MCU, a failed fan lets the heat sink run hot. Failing motor control unit: A degrading MCU can trip a genuine or false over-temperature fault.

Is it safe to keep using a Frigidaire washer with a E5B error?

Limited use only. This is rated a serious-severity fault.

How do I fix E5B on a Frigidaire washer?

Let the washer sit powered off for 30-60 minutes to cool, then retry a cycle. Check that the area around the washer and the MCU's ventilation isn't blocked or enclosed. If the model has an MCU cooling fan, confirm it's running.

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.