Ed • Mitsubishi Electric • Ecodan
Fault Code Ed Mitsubishi Ecodan: Hydrobox / Outdoor Unit Communication Error
On the Ecodan range, fault code Ed means the FTC hydrobox control board has lost communication with the outdoor unit.
Proof status : Manufacturer reference needed for the exact range
Source: Mitsubishi Electric Ecodan Installation Manual
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Founder of AskMarcel.app. Sheets are written from manufacturer documentation; the reference is shown when it has been verified.
In brief
Fault code Ed on Mitsubishi Electric Ecodan means: On the Ecodan range, fault code Ed means the FTC hydrobox control board has lost communication with the outdoor unit. Most common cause: S1/S2/S3 cable incorrectly connected, outdoor unit not powered, or software version incompatibility (if the control board has been replaced). First action: If you have just installed the system: verify that SW8 (or equivalent) is correctly set for the type of outdoor unit.. Call a registered engineer if the fault returns after basic checks or involves refrigerant work (F-Gas registered engineer required).
According to the Mitsubishi Electric Ecodan Installation Manual, fault code Ed indicates the FTC hydrobox control board has lost communication with the outdoor unit.
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Mitsubishi Electric code Ed: Marcel picks this code up for Ecodan and guides you, with the manufacturer reference when one exists.
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What does fault code Ed on Mitsubishi Electric mean?
On the Ecodan range, fault code Ed means the FTC hydrobox control board has lost communication with the outdoor unit.
S1/S2/S3 cable incorrectly connected, outdoor unit not powered, or software version incompatibility (if the control board has been replaced).
Symptoms
- The system does not start
- Display shows '--' for outdoor temperature
Diagnosis
1. Check Dip Switches
- If you have just installed the system: verify that SW8 (or equivalent) is correctly set for the type of outdoor unit.
2. Continuity Test
- Check the S1/S2/S3 interconnecting cable.
Repair and return to service — Mitsubishi Electric fault Ed
Check the wiring and power supply. Reset the system.
When should you call an F-Gas engineer?
Contact an F-Gas registered engineer if the fault returns after basic checks, involves refrigerant charging, or requires PCB or compressor replacement on Mitsubishi Electric Ecodan.
Field context
Fault code Ed most often appears in heating or hot water mode, particularly on Ecodan systems. The system does not start.
Frequently asked questions
What does fault code Ed mean?
On the Ecodan range, fault code Ed means the FTC hydrobox control board has lost communication with the outdoor unit.
What is the most common cause of Ed?
S1/S2/S3 cable incorrectly connected, outdoor unit not powered, or software version incompatibility (if the control board has been replaced).
How do I diagnose Ed in the field?
Check the Dip Switches: If you have just installed the system, verify that SW8 (or equivalent) is correctly set for the type of outdoor unit.
How do I resolve fault Ed?
Check the wiring and power supply. Reset the system.
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