Windscreen Washers Not Working

[Smart22186]

Okay, so I've not had the car long and have just noticed the windscreen washer is not working - I assume it's "pump related" as I get NO NOISE (no hum / no buzz /) from a pump.

I have done some digging on the site to see what I can find, unfortunately, most of the issues seem to be related to "blocked pipes or level sensors from back res to front res .. When I have the headlights on and do a wash (more than 4 washes) I still don't get any spray? I have checked the fuse in the footwell (number 38) no issues.

If the system had 1 pump I would assume that had failed .. but given it has a pump for lights and 1 for windscreen I'm a bit confused? Am I missing something? could there be another fuse? - I noticed in the handbook there is a reference to a washer transfer pump but again I assume this is the pump that moves the fluid from back to front so didn't explore that further

I'm yet to explore the driverside arch liner to see If I can physically see an issue or even see if the res contains a liquid?

[Smart22186]

Follow up question.. Given the front res has a level sensor which is designed to send a signal to the back pump to move water .. is it possible if the back pump has failed and not moving water to the front - the front could be "empty" and the sensor is deactivating the pump to prevent a "dry run" ? hence why I cant hear any pump noise?

In which case it could be a case of getting water to the front res (manually) to check level sensors ? would that work?