Ämne: Nibe SMO10 F2025 - problem after 11 years

[Nopinski]

Hi,

I’m sorry that I have to write in English, but I can’t speak Swedish. I live in Germany and Nibe doesn’t seem to be that known and thus there isn’t much information from an owner’s point of view. Hence, I’m trying it here hoping to get pertinent information to address my problem:
We have got a Nibe F2025 together with a SMO 10. The heat pump had been working without any issues until six weeks ago. From that point in time, the SMO 10 showed the error messag: Alarm fan (hopefully translated correctly) or in German - Alarm Vent.
After a restart triggered on the SMO 10 the heat pump worked for a week to appear again. The Nibe support was there and installed a new temp. sensor on Wednesday. But the problem is aggravated now since the pump has failed two times within two day.
As instructed I have opened the F2025 to get a reading from the display, which was S1 11. This messages pertains to a condition where the suction gas temp (T4) is lower than the evaporator gas temp (T7). However, this code isn’t used in newer SW versions of the F2025 as per my user manual. The displayed alarm on the SMO 10 isn’t listed in the respective user manual at all. Even if this alarm isn’t considered as problem anymore (and not considered by the updated SW) the question would remain why this condition hadn’t been occured for 11 years and does so now more and more frequently. Something seems to have changed - maybe through wear - but what could this be? Any hints, tips or information are greatly appreciated.
Thanks in advance and

Regards
Olli

[Carl N]

Hi!
I think you have an old version of 2025, in the newer model status 11 isn't in use.
In Nibe 2020 modell it says T4 is lower than T7 for status S1 = 11.
If the fan is working correct there is a problem with T4 or T7.
If you turn it off and wait an hour (with the cirkulation to the heat pump off) you can then read the temperatures direct after start up before the compressor starts.
Then both T4 and T7 should show about same temperature as T1 (outdoor temperature).
Change the one that differ most from outdoor temperature.

[Nopinski]

Regarding F2025 and F2020 version some things confuse me with respect to our heat pump. The user manual of our figther states F2025 as well as stickers on the outside of it. The sticker on the circuit board states “Nibe AB 618864, Fighter F2010, 640-128 L-103”, another one on an IC “Version 1.00”. And in the display of the SMO 10 under:
9.6.10 F2020 Heat Pump Type
9.6.16 3.00 Heat Pump Version
are listed.

From what I have observed meanwhile, the temperatur difference of suction gas temp and evaporator gas temp is as low as +2 degree. Not much to run into a negative temp. difference and, thus, produce this alarm condition, which is apparently not considered as such anymore because its deletion in newer SW versions.

When googling in German for similar problem, e.g. the same alarm, I only found one result of somebody with exactely the same heat pump/control unit dating back to 2012. In this case the temeratur sensors were changed and finally the circuit board. From then on all was fine.

The Nibe field service already mentioned that a new SW Version for the heat pump doesn’t consider S1-11 anymore. Thus my question ... can the SW on the circuit board of our Figther actually be updated or is a new(er) one required?

[Carl N]

I don't think you can update the software on a 2025, you have to exchange the circuit board to get a newer version.

[Josth]

The control board for F2025 is available e.g. through JS Energi sales: https://jsenergi.com/reservdelar-nibe/nibe-luftvatten/f-2025-8-kw-3x400v-064017/034-styrkort-f-2025-v120.html