So, if you have no idea of where the zone valves are, to check on this, you get technical, like any good NCE alumnus would. You get a multimeter capable of reading AC current, and see what the solenoids in your system are actually drawing.
That's funny. Unfortunately I only took enough EE courses to meet the graduation reqmts for my curriculum. And we're talking over 20 years ago. I'm thinking at this point that this is definitely not a DIY job for someone like me.