Bring a 20 foot sewer auger onto the roof.
Snake through roof vent.
He used a plumbers snake and he could put it down through the vent until it reached water.
He didn t find any obstruction.
Snaking a vent stack from the roof would entail carrying a heavy auger up there and running an extension cord to power it but milwaukee tool recently launched a revolutionary idea in augers.
Use a flashlight to shine a bright light down the vent pipe to look for further blockage you can reach.
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Insert the head into the vent opening and feed it down until you encounter resistance.
To continue feed the end of a garden hose down the vent and have someone on the ground turn on the water.
However the plumbers snake did come loose from the handle and now it is in the vent.
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And on homes that do not have a main drain cleanout accessing a clogged main drain through the roof vent could be your best option.
Start by trying to clean the roof vent and main drain with a hand held drum auger.
If you can see but can t reach run a plumber s snake down the vent pipe.
Crank the handle to work the head through the obstruction.