Hi All,

I've got an Oase 1700 pump in the pond.
When I turn it on, the impeller won't start, it just vibrates a little.
If I take off the inlet cap and nudge the impeller, it starts.
I then put the inlet cap back on, and it'll run indefinitely.

It's all clean, nothing is clogged, I've had the impeller out and
cleaned it, I've cleaned out the space inside the coils where the
impeller magnet are with cotton buds, it's all clean.

What could be causing this and how can I fix it?

Thanks.