AEG L16830 repeated pump failure

I have an AEG washer-dryer, model L16830, type P6359599. It has required three replacement drain pumps over the past six months, and has just failed again.

The symptoms of the fault are similar each time. The washing cycle fails at the rinse stage with error code E20 (corresponding to drainage failure according to the user manual). Sometimes, draining by hand, removing the filter and spinning the blades manually clears the problem, although I have seen no particular obstructions to the pump. Eventually, the pump stops working completely. If I watch the impeller blades on the drain cycle (with no water in the machine), they vibrate a bit but do not turn. Replacing the pump solves the problem… for a while!

The hoses inside the machine have been checked for blockages, and I snaked the drain hose. The resistance of the pumps before and after the fault develops remains around 250 ohms, but I don’t think this indicates much.

My current theory is that a fault in the electronics that control the motor is supplying too much current for too long and burning the pump out, but this is only a guess. I’m not too keen on a new PCB, as these are very expensive, but replacing a switch or sensor is realistic if that would fix the problem.

I would like to ask what the experts think – is this machine salvageable?

Thanks.