Low Voltage at Solenoids (15V) – Controller or Field Wiring Fault

RD1200 controller shows 24VAC at transformer terminals but only 15VAC at solenoid leads with field wires connected.

Diagnosis

Disconnect field wires (zone + common) at controller.
Measure voltage at controller terminals during zone activation.
24VAC with wires off: Controller OK; short in field wiring (likely common wire).
15VAC with wires off: Controller output stage failed—replace panel (~$175) or unit.

Irritrol RainDial 12-station panel fits existing enclosure. Labor ~$75.

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