Toilets, sinks, bathtubs and other fixtures connect to vent pipes through the plumbing. Vent pipes maintain equilibrium in the drainpipes, replacing air washed down with the waste water with fresh air from outside. The pipes also transport sewage gases in the drainpipes safely outside the house. A toilet with a clogged vent pipe won't keep its water level to an optimal height and have problems flushing, making gurgling or burping noises.
Climb up a ladder to get onto the house's roof. Place the bottom of the ladder on a sturdy, level surface and take your time climbing up. Once on the roof, watch where you step to avoid tripping or slipping off.
Look for the vent opening that sits roughly above the bathroom where the toilet is located. Remove any obstructions from the top of the vent pipe or any covers.
Tie a piece of wire or rope to the flashlight and slowly lower it down the vent pipe, allowing you to see down the pipe.
Climb off the roof and connect a high-pressure attachment to your garden hose. Hold the end of the hose as you climb back up the ladder and onto the roof. Spray water down the vent pipe and listen for sounds of the water rushing down or accumulating in the pipe.
Shine the flashlight down the drainpipe again, looking for any water standing inside the vent pipe. If you see standing water, contact a plumber for further assistance, as this indicates a severe clog in the vent pipe. Climb off the roof and remove the ladder.