Hardie Valve Requires Bleed Screw Open for Pressure – Solenoid or Port Issue

Valve Only Works with Manual Bleed Open

On a Hardie valve, zone 1 only delivers adequate pressure when the bleed screw is partially open. Closing it kills pressure. The solenoid clicks but doesn't fully release the control water.

Two Possible Causes

1. Solenoid plunger stuck or dirty: Remove the solenoid, pull out the plunger, clean it and the bore. Reinstall and test.
2. Dump port clogged: The tiny hole where the solenoid vents control water may be blocked. Cleaning it is difficult due to its size; replacing the valve bonnet (top assembly) is often more practical.

Start with solenoid cleaning. If that fails, replace the bonnet—it contains all working parts and is cheaper than a full valve replacement.