Whale Watermaster External Pump not working

Try cleaning the contacts on the pump and the inlet if it has not been used could just be bad conections

I'd have thought that the external pump needs to be selected somewhere before it knows to pump. Is there some kind of master/control panel in your vehicle?

This about a Bailey caravan rather than a motorhome but it may hep.

You Tube video

Once the whale submersible pump is plugged in to the socket, go to the Seattle control panel, use the down key until you see fill and enter, this should activate the pump. You will need to manually stop it on the panel when the water container is empty otherwise it will damage the pump.

Thanks for all your replies. It was as you suggested on the control panel, selecting "Fill Internal Tank". I'd tried this before with no joy, but it turns out this was because my water probe was playing up and was registering the water level as 100%. The external pump stops once the level is 100% and so it just wasn't kicking in. I recalibrated the sensor (although it probably needs a new one!) and hey presto the external pump kicked in when I tried it again!