Beko DCU 8280

[DP]

My own appliance
Tank full light came on and dryer was not drying the clothes. Collector tank top left was empty
Removed the condenser unit and flushed both ways
Removed the back and looked at the pump gubbins- float was high up and operating the switch to display the TANK FULL led
Removed the sump and pump. Pump impeller was clear ( removed the shroud around the pump impeller) and spindle was free to rotate
Removed all the water from the sump and any lint within.
Put fly lead on the motor- it ran to discharge water into the tank at the tap

Removed the pcb. Relay 1 applies 240 to the pump
Relay is ALJ112, 12 volt 700 ohm coil resistance and contact is rated at 3amp. Similar relays found on some boiler pcbs that run the fan. Contacts don’t last to eventually not switch despite having operated. Have order same relay which will be changed hoping that will resolve the issue.

You pros here, am I on the right track or the wrong ball park

Thanks for reading

 

[jj4091]

Don't know anything about your machine but it sounds like you are on the right lines. The only question I would ask is when the float is operating the tank full switch is it because of the water level and not just mechanically stuck in that position. Secondly is there another sensor that operates the relay that you mention. Is it actually an electromechanical or is it an electronic relay?

 

[DP]

Thanks for posting
Float operates a microswitch. These sump indeed is full of water
Relay is electromechanical not a triac
The processor output switches the relay via interfacing transistor.
Another sensor feeding into the processor causing the pump relay not to operate is a possibility hence getting a replacement relay, will change relay and see. Better this then get a new PCB and dryer still fails to function

 

[jj4091]

If you cannot meeasure a voltage across the coil pins in the socket then you should be able to tell if it's energising by pulling it in and feel it click on when you put it back. Or is it soldered to the pcb? At least that would tell you if it is just a contact problem.

 

[DP]

Relay soldered onto the board. Coil resistance is tad over 700 ohms. Defect possibly the contacts are worn out switching inductive load (motor)
Dare say can power the relay via external 12 volt supply and check contacts make, unfortunately the variable bench power supply is at friends house. Lot of components are SM devices so access difficult