Help Tunze wavebox problem

[wil0311]

I can't find an answer for my question. Does anyone know if the pump on the wavebox is supposed to run continuously with pulses or stop completely between pulsing. I have 2 of these tunze waveboxes and the newer 6261 pump that runs continuously is the one that I'm thinking isn't working as intended.

Has anyone else had any similar problems?

Thanks,
Jason