You could be experiencing a failure in the valve. Open the box where the
water comes in from the street to yout sprinkler control box. One of the
wires might be off the valve...or chewed off by mice or some such!

jin wrote:
Hi,

I am experiencing a weird problem with one of the zone (zone 1, that is).
It does not open in either manual mode or auto mode.

However, I discovered that if I leave zone 1 in manual open mode,
and when zone 2 is open in auto mode, both 1 and 2 open.

The controller is a fairly old 2-wheel type controller and I never had
any problem with it before.

Any suggestions, guesses as to what's going on?

Jin