TDI Aux.heater - circulation pump problem?

So, I'm going down the road of troubles with my Octavia. Now the only thing remaining is the diesel heater, but it has a few fault codes and wont start. 

I've read up on a bit of info, and as far as I understand, the heater should be unlocked in VCDS, I think I'm able to figure out that part. But as far as I can understand, the circulation pump is the problem, but I cannot find the heater and parts in the engine bay. 

Quote

 

Address 18: Aux. Heat (J364)       Labels:| 5Q0-963-272.clb
   Part No SW: 5Q0 963 272 C    HW: 5Q0 963 272 C
   Component: STH-MQB       006 0069  
   Coding: 9309
   Shop #: WSC 73430 031 00063
   ASAM Dataset: EV_AuxilParkiHeateWOS 002014
   ROD: EV_AuxilParkiHeateWOS.rod
   VCID: 36352A8FC8CFD21ABDF-8062

   Auxiliary heating remote control: 
   Subsystem 1 - Part No SW: 5Q0 963 513     HW: 5Q0 963 513 
   Component: R149 T91-LIN  003 0301 
   Serial number: 00000000000001039072

2 Faults Found:
0139 - Recirculation pump 
          B1382 15 [00001001] - Open or Short to Plus
          Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Priority: 3
                    Fault Frequency: 14
                    Reset counter: 191
                    Mileage: 289548 km
                    Date: 2023.06.27
                    Time: 14:10:25

                    Parking heater: operating condition: System malfunction
                    71
                    Coolant temperature of parking heater: 21  C
                    Coolant temperature: 18  C
                    Engine running status: detected
                    Fuel level: 12 l
                    Heating performance: 0 W

 

0135 - Heater Unit Locked 
          B138F 00 [00001001] - -
          Confirmed - Tested Since Memory Clear
             Freeze Frame:
                    Fault Priority: 2
                    Fault Frequency: 1
                    Reset counter: 191
                    Mileage: 290389 km
                    Date: 2023.10.20
                    Time: 19:24:32

                    Parking heater: operating condition: After-run - burnout
                    71
                    Coolant temperature of parking heater: 5  C
                    Coolant temperature: 3  C
                    Engine running status: not detected
                    Fuel level: 11 l
                    Heating performance: 0 W

 

I think I've found some used parts that might fit, is this the correct pump?

Any help is appreciated. I might be so lucky it's just a fatigued cable, but I really can't find it.