Question
Controller displays error 1 - what is this for ?

Answer
Hi Clair

This means an faulty selenoid at valve 1, or an short on the wires to valve 1. Check the wires on port # 1 on the controller, make sure they are not loose or touching one an other. Check the wires from the controller to the valve look for loose connections or rust wires.  
If the error continues replace the selenoid, it cost about $8 at Home Depot.

Regards
Guillermo