I cannot find a manual for the Darlac DW253.
It appears the timer is set by moving each selector knob.http://www.watermate.co.uk/secure/uploads/DW253%20(Small)%20new%20darlac%20pop.jpg
Knob on right is Run Time:
This is how many minutes timer will run each time.
Set run time from 1 minute to 120 minutes.
Knob on right also has ON-OFF override.
Knob on left is Frequency:
This is how frequently the timer will turn ON. Once per hour, once per each 2 hours ... once per 24 hours ... once per 72 hour ... once per week.
So set frequency to 48 and set run time to 20, then every 48 hours the water will turn on for 20 minutes.
To turn timer off, move right knob to OFF.
For continuous watering, turn same knob to ON.
This timer is battery-powered, probably 9 Volt, but maybe AA.
Battery carriage appears to be located on front below the function knobs.
Typically, water timer batteries last one season.
Timer can be connected to household spigot, or connected to any passive water supply for example rain barrel or tank.
Appears to have standard female hose thread on top, or possibly 1/2 pipe thread, and quick connection on bottom.
Plastic water timer exposed to freezing temperatures can crack. Drain water out of timer during cold weather.
Generally if water timer stops working: replace battery, clean battery terminals, and if functionality is not restored, then buy another timer.
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