3/4" backflow valve drips
Watts Series 009 valve is 7 or 8 years old. Periodically it discharges as designed, but now it has started to drip constantly. I installed the kit (large o-ring, diaphragm, and rubber seat) and cleaned everything carefully. It still drips. I called the water company and they said there were no significant variations in water pressure going on currently. (It dripped before I installed the kit, so I don't think I caused it.)
The valve does not drip if we are using the water, i.e., if the toilet is running or we're running water anywhere- even just a small amount.
I appreciate any help. Thank you.