Question
I have a brand new Hunter SRC Plus 600i  controller since July 2010. It works fine with 2 old 1" Hardie valves and one 1" Buckner valve. My entire system has 3 zones and about 20 heads
I installed the system myself in 1972 using a Tork Time controller and the above mentioned 1" valves.
I tried to winterize my system as I have done successfully since 1972.(never had a problem)
Now by using the new Hunter SRC Plus, my valves do not open as compressed air is introduced (80 PSI +/-)
I run one valve at a time at the SRC Plus, and no air is allowed through. The output voltage at the controller is 28V Open Circuit and  the solenoid coil resistance measures 20 ohms (at each of the 3 valves)

I have changed wire size, from 20Ga to 18Ga and still no luck.

I repeat, the Hunter controller works fine with water, but once I turn it off and start my air compressor nothing happens.I am stymied. What am I doing wrong?
Your help will be GREATLY APPRECIATED. Please help as our weather is getting cold and I don't want any freeze ups.

With many thanks,

Si  

Answer
Hey Si, you probably are doing nothing wrong, the problem is more than likely with the valves themselves. The diaphrams probably need to be replaced. What you could do is manually turn these valves on at the valves themselves. On the top of the valve you will notice a star shaped piece of plastic, what this is , is a bleed screw. with the pressure on the valve, simply un-screw this screw (counter-clockwise) and you should hear air leaking out of the top of the valve, and the valve should turn on for you. Good luck and have a great day.