Sierra 830, 860, 840 instruction manual Maintenance

3.Unscrew the coil cover with a 11/16 inch wrench. Remove the coil and coil enclosure. Note the location of any washers or spacers for re-assembly.

4.The small circuit board may be separated from the main board to ease removal of the coil. To separate, first remove the mounting screw located in the center of the main circuit board and carefully pull the two boards apart.

5.Remove the four 1/4-28 socket head cap screws at the base of the valve. Separate the valve from the flow body, taking care not to lose any small parts.

6.There are three O-rings sealing the valve assembly: one be- tween the base and the flow body, one under the valve seat (orifice), and one on the top adjusting screw inside the valve. Inspect the O-rings for damage and replace as necessary. (You should replace all O-rings whenever the valve is disassembled.)

7.Inspect the valve seat and plug for corrosion or roughness and replace as necessary.

8.Re-assemble the components. When the controller is installed in the system, leak test the connection.

9.Adjust the valve for proper operation as given in the controller valve adjustment procedure.