Stuck valve?

I'm a commercial winemaker with limited refrigeration knowledge. I believe I have a stuck valve on a French made champagne bottle neck freezer. There's no pressure in the capilary tube to trigger the cut-in contact. If I manually close the contact, the compressor starts. I've tried open and closing, and tapping the valve. Is there any way to unstick a valve short of draining the refrigerant (404A) and taking the valve apart?

I did not know there was such a thing as a champagne bottle neck freezer.
The things I learn on this Forum!
Need a little more info.
I assume that this is the Liquid Solenoid Valve.
What type is it? Sporlan, Danfoss......? Does it have a manual opening stem? Is there a Filter Drier installed? Could you be low on charge?

Yes, interesting idea that..

Found this description of WHY they freeze the neck...
http://www.prestonpeak.com/storyof_serisier.html

Might help understand why.

Are you sure there is pressure behind the valve?

Are you sure there is any gas in the system?

Sounds to me like it's got no gas in it.

Chillin:) :)

sounds like you have gone as far as you can,you need a engineer and telling them you make booze will gaurentee a que outside in notime !

hi- does anyone know if this system can be pumped down?then he could check the valve?does sound like theres no gas though.what about the sight glass?