New Pump Relay Not Activating: Voltage and Compatibility Check

Pump Start Relay Won't Engage from Controller

New Flotec pump, digital 4-zone timer, and pump relay installed. Relay clicks when manually activated but not from timer's automatic or manual start.

Diagnostic Steps

1. Measure control voltage: Should be 24VAC at relay's low-voltage terminals during pump start command
2. Verify relay coil rating: Must match controller output (typically 24VAC, 50/60Hz)
3. Check controller pump/MV terminal programming: Some controllers require enabling "pump start" or "master valve" in settings
4. Test relay independently: Apply 24VAC from known source to relay coil terminals

Common Mismatches

• Controller outputs 24VAC but relay expects 120VAC coil (or vice versa)
• Controller's pump terminal is current-limited; relay coil draws too much
• Wiring error: common wire not connected to relay's common terminal