Samsung gen.5 AE160JNYDGH + AE120JXEDGH

[Jonas]

Hi, 

My system is around 4-5 years, warranty is not valid any longer. 
While using Floor heating ('Water law' mode with all zones open) + DHW, I encountered a strange issue (No errors). 

The issue:

1. Flow pump starts;
2. Heat pump starts to run; 
3. After 3 minutes, 3 way valve switches to DHW (at the time DHW is 47.5 degrees celsius, keeping it at 48 degrees celsius - start at 5, stop at 2 - default setting values);
4. Warms up to the DHW temperature or slightly lower (takes a couple of minutes ) then switches back to the floor heating by releasing hot water into the floors;

While EHS is working as described, DHW temperature drops much faster what results in increased consumption, floors doesn't feel comfy at all  

Worth to mention, if heating or DHW only is used, system works just fine. 

Has anybody encountered anything similar? My best guess is faulty PCB..

/ Jonas

Edited October 30, 2022 by Jonas

[ProDave]

My understanding is most heat pumps only heat DHW or space heating (UFH) at a time, never at the same time, so is the diverter valve playing up?

 

Could the fact heating or DHW work fine on their own confirm that?

[Jonas]

Hi, 

I ran the test mode and the diverter valve switches just fine.
So independently all seems to be okay. While working together something strange happens where diverter valve triggers and flow starts running to DHW, after certain time diverter switches back. 
 

[Jonas]

Update: 

Found out that if when the temperature of DHW is higher (47.5) > compared to temperature selected on heat pump (47.0) everything works fine. As soon it goes beyond 47, it starts to mess things up.