First, the easy question. I sort of know the answer, but want some input from anyone with prior experience. I got a call to turn on a system that is finally out of warranty with one of the management groups I sub for. The backflow is a Wilkins 950xlt DC 1.5". It failed. Second check is shot. I open the device up and the plastic seat is lose and the o-ring for the seat is hung up on the spring. To get a "feel" for the condition of the system, I put the cap back on #2 with the guts missing. The cap is hard to start, but once started makes about 2 turns and gets very hard to tighten up. The cap o-ring is also somewhat stretched. This device has only been in place for about 18 months. Does it sound like it froze and the check body is slightly warped to you? What are the odds that a new check seat and o-rings will allow the device to function? I have already warned those that need to know that they may be looking at a new DC install. Also, the bottom of the check seat is probably the reason for my stuck zone at the end of the run. I didn't get that far. I took the failed device back out of service and had to make my next appointment. I've ordered the parts. They were not expensive, so we will try to salvage the backflow. If it will pass with new parts, I will save the owners a few hundred bucks Now, for my hard question. I have an account that another company installed about 4 years ago. I took over the account when the litigation between the installer and the builder began. For the last 3 years, I have replace 2-3 solenoids per year. The date codes are mostly 01's but a few are early 02's. this would be common in this are for a late '02 install. The failing solenoids are WM on silver bullets. The controller is a ICC w/ a total of 24 stations, 22 are in use. There has not been a lightning strike at this site that anyone knows about. Is it possible to stress/strain solenoids if the crew didn't know what they were doing wired the controller wrong and fried it the first time? I'm thinking hooking the 120 to the 240 instead? I have replaced almost half of the solenoids and this system isn't 4 years old yet. Any thoughts on why this has happened would be great.