Had a run of these types (such as S51M53X2GB/N3) with water in the base activating float antiflood/ seeping into heat-pump element. Upon visit machine functions correctly with no visible leaks.
Water is often yucky yellow tint.
Where/how does the leak occur?
I check;
Door seals – if they get gunged near door hinges, water can sleep through and I directed through white plastic channel into center of base.
Spray arms – if they develop a split, water can force through seal same as above.
Empty/drain pump chamber and function/sink fitting.
Waste hose high enough so sink water can not back fill.
Torch in all areas of machine during cycle, looking for leaks.
If plastic to metal tub inspect seams for leak/signs of leak yellow crusts etc.
Are they slow leaking through the heat-pump?
If it’s drain pump or flow wheel related (overfilling) why is water not clear and why do they always function correctly when I visit?
Any help appreciated, thanks.