Troubleshooting Rain Bird 1804 PRS SAM Heads That Won't Pop Up

Intermittent Pop-Up Failure on New Rain Bird 1804 PRS SAM Sprinkler Heads

A user installed 14 Rain Bird 1804 PRS SAM heads (7 per zone) on new valves. During each watering cycle, a few heads fail to pop up on their own but work fine when manually lifted. The problem shifts between heads, and system pressure appears adequate. The system was flushed and checked for debris.

Key Differences: PRS SAM vs. Standard 1804 Heads

The PRS SAM series includes a built-in check valve and pressure regulator, requiring a minimum of 25 psi to operate correctly. Standard 1804 heads need only 15 psi. If system pressure is marginal, the higher requirement can cause inconsistent pop-up.

Diagnostic Steps

1. Verify zone flow (GPM): Measure output at the valve using a water meter or timed bucket test.
2. Check nozzle GPM: Look up the nozzle chart (e.g., 15H = 2–3 GPM, 15F = 4–6 GPM). Multiply by number of heads to get total zone demand.
3. Confirm pipe sizing: ½″ PVC handles 4–6 GPM; ¾″ handles 8–12 GPM; 1″ handles 15–20 GPM.
4. Compare supply vs. demand: If zone demand exceeds supply, pressure drops below 25 psi, causing heads to stick.

Solutions

• Replace PRS SAM heads with standard 1804 heads (lower pressure requirement).
• Reduce heads per zone (e.g., 5 per zone) and use the spare valve.
• Increase supply pressure or pipe size if possible.

Without knowing exact nozzle sizes, pipe diameter, and measured GPM, the exact cause can't be pinpointed, but pressure deficiency is the most likely culprit.