Zone 1 Pressure Drops to Zero After Winterization

One Zone Dead After Spring Startup: Leak or Valve Issue

4-zone system. Zones 2,3,4 work at 50 PSI. Zone 1: pressure drops to 0, heads silent. System winterized last fall.

Two Main Causes

1. Leak on zone 1 – Run zone 1 and wait. Look for soggy spots, bubbling, or extra-green grass. Leaks can be slow to surface.
2. Flow control shut off – If winterizer closed the flow control on that valve, it won't open. Check the valve's flow control knob.

Electrical Check

If no leak and flow control open, test for 24VAC at the valve when zone 1 runs. No voltage = wiring or controller issue.

Start with leak search and flow control check.