Hydrotek 4000 Low Pressure Daytime—K-Rain Timer Solenoid or Supply

Hydrotek 4000: can't run daytime (low pressure). Manual black valve worked once then stopped. Hums sometimes. K-Rain timer.

Clarification

Black K4000 = hydraulic valve (not motor). "Hums" = solenoid buzz on backflow preventer.

Diagnosis

1. Solenoid on backflow: If faulty, no water passes
2. No pump + city water: Check gate valve OPEN, pressure adequate
3. K4000 internals: Open valve, check disk stem for debris/frogs/lizards

Pump Check

If pump system: verify pump runs, relay works, voltage correct.