My reduced pressure zone (RPZ) backflow preventer is discharging water from the relief valve. Is there an easy way to diagnose the problem?
Yes. Follow these steps. First, close #2 shut-off valve. If the discharge stops, the problem is a fouled second check. If discharge continues, open #4 testcock. If the discharge stops or is reduced, the problem is a fouled first check. If the discharge continues, the problem is most likely in the relief valve. Disassemble and clean the affected components and remove any debris from the backflow preventer. If any parts look damaged, they made need to be replaced.
