Grey water won’t drain

[De Tortu]

Switch operated Gulper 220 losing suction

I’ve removed it now four times, got it working and refitted and all is good. After a few idle hours it won’t suck water.

Any suggestions?

The pump is new. The reservoir is clean, all pipes are clear of obstructions.

[SailingHarmonie]

Insufficient information.
Is the pump above the sump?
When you removed it, and "got it working" what did you do?
What is the length and lift of the input to the pump? The outlet?
You say the pump is "new". Has it ever worked? Is the whole system new or just the pump?

Almost surely an air leak causing a loss in prime... but impossible to be sure.

[De Tortu]

I since found a poor connection on the outlet side and am testing it this afternoon

Thanks for your reply, I’ll let you know how it goes