The RD600/900/1200-R RainDial Timers may display P:On or P:Off on the LCD.
This is one of the features in the new -R series of Irritrol sprinkler timers. It’s described in the manual in more detail, but basically does this. The Sprinkler timer has a pump control signal that normally turns on when a particular valve is turned on. Most people I know don’t have a pump to boost pressure in their irrigation system so it’s not a common feature for the general urban irrigation system. If for some reason you did not want the pump to come on when a particular valve was on, you can turn it off by setting the main switch to the Set-Programs position, the dial to the valve you want to change the pump settings for, and then press the Manual-On button. It will toggle between P:On and P:Off each time you press Manual – On.
If you don’t have a pump, it doesn’t matter whether you turn this feature on or off. If you do have a pump, you’ll know what to do.
If you’re not expecting this to appear on the LCD, you probably need to slide the switch to the “run” position instead of “set programs.
I hope that helps,