I am in a bit of a bind. I am working on a 3 zone system that has 20 Volt DC, NOT AC, valve controls. They are called Electro Zone and apparently went out of business in the early 70s. I cant find any info on them and hoping someone here may be able to lend some assistance.
Three coils and they all OHM fine. Coil issue can be ruled out. With one zone on, I read 19.4 volts, with two or three on, I read 18.1 volts. I wonder if this is enough to open the valves or not. I am really not sure where to go from here or how to troubleshoot these valves. Any advice is appreciated. Thanks.
There was a discussion here in 2005 about them.
Here is another one in 2011 about them.
It seems that the best thing to do is replace them. It shouldn't be a biggy. The newer Taco zone valves work well. I always used wax motor 572's but I was happy with the last ESP Taco valves.