Ames Fire & Waterworks LFM500, LFM500N, LFM500Z Lead Free Stainless Steel Reduced Pressure Detector Assemblies - Manual (Page 7)

7
Troubleshooting Guide
Difficulty Possible Cause Correction
#1 check is fouled Remove and Clean #1 check
Relief valve discharges water Relief valve does not properly close Service relief valve
while system is not flowing
Municipal water pressure is fluctuating Install check valve upstream
of backflow assembly
Fouled relief valve seat Service relief valve
Relief valve does not Incorrectly installed diaphragm Remove diaphragm and
shut off properly correctly install
Damaged rubber surface on piston Replace with new piston
Damaged or plugged pressure hose Repair or replace hose.