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Nelson EZ Pro 8306: Intermittent "P" Code on Various Zones

Nelson EZ Pro 8306 shows "P" code intermittently on different zones at different times. Works sometimes, fails others.

Manual's Three Causes for "P" Code

Wiring issues - Disconnected, shorted, or damaged wires/solenoids
Too many solenoids per zone - Only ONE solenoid allowed per zone terminal
Lightning damage - Controller damaged but intermittently functional

Troubleshooting Priority

Check all wiring connections - At controller and every valve box. Look for corrosion, loose wire nuts, damaged insulation
Verify one solenoid per zone - No daisy-chaining multiple valves on one terminal
Test solenoids - Resistance should be 20-60 ohms each
If all wiring/solenoids good → Controller likely has lightning damage

Why Intermittent?

Temperature changes expand/contract wires, making marginal connections work sometimes. Moisture affects corroded splices. Lightning-damaged controllers often work until thermal stress triggers failure.

Irrigation: Irritrol KwikDial Two Solenoids Per Station Fail After 3 Years: Voltage Drop Under Load; Testing Rain Bird ESP‑6 Wiring and Solenoids with a Multimeter; Replacing 20-Year-Old EZ-1 Timer (Rain Bird ESP Series Recommended); Rain Bird MSC-SAT-24: Single Zone Not Activating; Hunter XC Station 1 Won't Activate from Controller—Valve Works Manually; Low Voltage at Solenoids (15V) – Controller or Field Wiring Fault; Hardie RD-600 Shows "75", Zone 1 Runs Forever – Replace Controller; One Zone Low Pressure, Pump Cycles – Valve Not Opening Fully; Connecting Multiple Solenoids to One Common Wire – Waterproof Wire Nut; Fixing a Hydrotech 4000 Indexing Valve That Skips a Zone

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