Mitsubishi Heavy E8

High

KX / FD — E8 = heating overload (abnormally high indoor heat exchanger temperature) or indoor heat exchanger sensor (ThIR) fault/short; drain pump/float switch issues also possible. NOT 'address collision/connection error' (that's E2/E12/E46).

Mitsubishi Heavy E8: E8 = heating overload (abnormally high indoor heat exchanger temperature) or indoor heat exchanger sensor (ThIR) fault/short; drain pump/float switch issues also possible. NOT 'address collision/connection error' (that's E2/E12/E46). This fault noticeably affects operation.

Possible causes

Multiple units same address / bus error.

Check steps

Check addressing & bus connection.

Affected parts

Schwimmerschalter
Kondensatpumpe
Wärmetauscher-Fühler
Reinigungswerkzeug (Lamellen)

Safety note

Low voltage — work carefully.

Source: Mitsubishi Heavy resmi servis kılavuzu — DÜZELTİLDİ: MHI (Mitsubishi Heavy Industries) / 3D Technical Support, "ERROR CODES – R410A" reference sheet (R410A Systems, FD Split/KX4/KXR4 series), E8 row: "Overload in heating (extraordinarily high indoor heat exchanger temperature)." / "Indoor unit heat exchanger sensor [ThIR] failure (…

Reviewed by Anıl Güzeldemir — in the refrigeration machine room since 2006, developer of Enthalio.

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Related fault codes

High pressure fault.E40 Communication error during operation.E5 Outdoor DC fan motor abnormalityE48 Compressor start failure (CM1/CM2)E59 Drain water level abnormality (float switch)E9 Communication error indoor ↔ remote controllerE1