I Must've Got the Bad Solenoids Too
Back in August of '03, I had a 32-zone sprinkler system installed in my lawn. All Weathermatic valves. My installer has been out at least 15 times in the first two years replacing solenoids as they went bad. After about 10 service calls, he once mentioned that there was a 'bad batch' out there and he was going to replace all the solenoids. I'm not convinced he got them all, or if he did, the ones he replaced them with weren't much (if any) better.
This past weekend I had two more go out on me. One with a 6/04 (may have been 7/04, the arrow was between the 6 and 7) date on it and was all black plastic. The other one (didn't check the date before reinstalling it until I can get it replaced, allowing me to keep the main valve on and running the rest of the system) was black but the sleeve that the plunger rode in was a cream-colored plastic. I also didn't know at the time to note the wire size.
I, too, have only one valve on at a time and use a Hunter ICC controller. Many of my neighbors have the same system but I haven't heard of any of them complaining about solenoids.
What I'm wondering is if there is another brand of solenoid that I can use to replace the Weathermatic ones with so that I might get some extra life out of them. Home Depot sells 'universal' replacement solenoids that fit but don't operate properly. I'm not too hip on spending $12 a pop only to have to replace them again year after year.