Originally Posted by Gorhad
The valve is called a Richdel 205TF solenoid valve. It has a hex head plastic screw on the rhs, the central has a thumb wheel and forward has the solenoid.
If i unscrew the solenoid slightly then unscrew the hex head screw at the back water flows through. If i screw either the solenoid or hex head screw back in water stops
The solenoid and controller are both 24volt matched. You can hear/feel the solenoid click.
You should make sure the "big thingy" at the top is completly open (turn counterclockwise until it stops and back of about 1/4turn) You shouldn't need to turn the solenoid if you open the bleeder valve but you should get some water coming off the bleeder valve.
After making sure the dang thing is open; try turning the solenoid slowly (with the bleeder valve closed)n until the valve opens, or it comes off. If you don't have flow after it comes off; replace the entire valve; just unscrew the hex bolts holding down the top on the old one, pull all of it out slowly (study how the stuff came out) and reverse the proceedure using the new one. You don't need to cut the valve out of the line... just change what's inside. That's a cheap valve, I doubt you can get parts.
By the Way... make sure the solenoid faces the direction of the water... in other words, the flow should come from the other side of the valve the solenoid is on.
One of the most common errors my slave... err workmen make is tightening down the solenoid too hard.
Had to change my ex-wifes diagphram once... nasty job. Needed two hands and a quart of valvoline. No screws.