Dan, it sounds like your weak water pressure, compared to the pressure in the boiler system, could be the reason for the dripping. If you close an isolation valve downstream of the backflow preventer, and bleed off the pressure, does the dripping stop? In other words, increase the pressure differential across the backflow.
Dan, it sounds like your weak water pressure, compared to the pressure in the boiler system, could be the reason for the dripping. If you close an isolation valve downstream of the backflow preventer, and bleed off the pressure, does the dripping stop? In other words, increase the pressure differential across the backflow.