Viessmann Error Code EC51: Outdoor EEPROM error (Mini-Split)
Viessmann error code EC51 on a mini-split means: Outdoor EEPROM error. It is also called Viessmann diagnostic code EC51.
Homeowner? What Viessmann code EC51 means for you
Call a technician Your ductless mini-split is reporting: Outdoor EEPROM error. The ductless mini-split has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.
Safe things you can check yourself
- Check the remote: fresh batteries and the right mode (Cool, Heat or Auto).
- Check the breaker and the outdoor disconnect; both should be ON.
- Open the front cover of the indoor unit and rinse the washable filters if they are dusty; let them dry before putting them back.
- Keep the outdoor unit clear of snow, ice and leaves.
- Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.
Call (647) 657-2977Book a service call
Licensed technicians serving Vaughan, Toronto and the GTA.
What does Viessmann error code EC51 mean?
The outdoor main chip gets no answer from its EEPROM memory chip. Outdoor board shows E0; 48K HH shows F4.
Applies to: DLCM(R/H)B multi-zone outdoor units with DLFSHBH high wall indoor units (Midea, Carrier, Viessmann)
Common causes of Viessmann code EC51
- Bad outdoor main PCB
Viessmann models that use code EC51
DLCMHBH24CAKDLCMHBH30DAKDLCMHBH36DAKDLCMHBH48EAKDLCMRBH18BAKDLCMRBH36DAKDLCMRBH48EAKDLFSHBH09XAKDLFSHBH12XAJDLFSHBH12XAKDLFSHBH18XAKDLFSHBH24XAK
Other Viessmann Mini-Split codes
All Viessmann Mini-Split error codes →
Viessmann code EC51: homeowner questions
What does Viessmann code EC51 mean?
Outdoor EEPROM error. The outdoor main chip gets no answer from its EEPROM memory chip. Outdoor board shows E0; 48K HH shows F4.
Is it safe to keep using my ductless mini-split with code EC51?
It depends on the cause. The ductless mini-split has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.
Can I reset Viessmann code EC51 myself?
You can try one reset (power off for 30 seconds, then on). If Viessmann code EC51 comes back, the cause is still there and a licensed technician should check it.
Who can fix Viessmann code EC51 near me?
Aurora Star Tech Inc. repairs Viessmann ductless mini-splits in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.
Homeowner help: AC Running But Not Cooling: What to Check · Heat Pump Not Heating or Blowing Cold Air
Troubleshooting guides
- Indoor unit leaking water All brands · Mini-Split
- Poor capacity / high head All brands · Mini-Split
- Water leaking All brands · Mini-Split
- Discharge the inverter capacitors before service Viessmann · Mini-Split
- Display shows a strange code or does not answer the remote - DLFSHB indoor Viessmann · Mini-Split
- Multi-zone: one room heats, another will not cool - DLC multi-zone Viessmann · Mini-Split
- Read live data with the outdoor check button (SW1) Viessmann · Mini-Split
- Run the automatic wiring / piping correction Viessmann · Mini-Split
Source: DLCMRBH/DLCMHBH Multi-Zone Outdoor Service Manual (sold as Midea, Carrier and Viessmann Vitocal 200-S; Viessmann doc 6225551-03, 12/2024), Table 23 Outdoor Unit Error Display p.26; diagnosis p.45; Carrier MS-DLFSHB-01 High Wall Ductless Service Manual (04/2021), Table 9 p.17. Written in our own words as a summary; always check the original manual.
General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.