North Point New gate valves stuck black and grey

[johninpebble]

First day the grey valve did not return 100% then 2nd day the black gate valve did not return 100%. They both have aprox. 1/2 inch left to travel in. Grey water flushes as it should Black water drips but does not flush anywhere close to what grey water does. The assessment would be material from construction is in line and preventing flow and preventing fully shutting off valve. I assume the fix is a snake going in the 3inch external pipe. Any suggestions?

[16WhiteColly]

Work them back and forth and see if you can dislodge the obstruction. May be a plug from when they installed the vent or plumbing lines that is lodged in there. Maybe run a good flow of water thru while doing so. I would not snake.