Water Purifier not accepting Filtration (Sand)

Did you have water hooked up? Right now, the Water Purifier won't ask for sand until it has all the pipes hooked up and water ready to be purified.

You may need to check that the pump is working. Reloading the game or deleting and rebuilding the pump sometimes fixes it.

Your liquid bridge is reversed at the output of the purifier. Without working output it doesnt get input water and they wont deliver sand.

"empty pipe" = input error ; "not pumping" = output error (can be handy later  )