Clogged/frozen Vent Line

paul p

I had my waste line augered a few weeks ago. It worked fine for 2 weeks. I now get a trickle of water coming up through the vent line at the curb. Its clogged again.

I pokw a pipe down the line and can only get to a depth of 3'. The temperature on the east coast in the us is in the teens. I am asuming there is ice in the vent line. Water does come up the vent line.

Is there any thing I can pour in the vent line or wash through the sink in the basement to un-clogg the obstruction.

Thanks