The water level in my commode is surging. The level in the commode is constantly moving, about 1/2 inch in the level. You can watch it move up and down, even though nothing is running in the commode. The commode flushes with no problem. I have my own septic system and the drainage lines do not appear blocked. Is this an indication of a potential problem?

The water level in my commode is surging. The level in the commode is constantly moving, about 1/2 inch in the level. You can watch it move up and down, even though nothing is running in the commode. The commode flushes with no problem. I have my own septic system and the drainage lines do not appear blocked. Is this an indication of a potential problem?

If the water in the bowl surges and changes the bowl level it points to a vent problem in the system. What happens is that when somthing's drained or flushed it puts a vacuum in the system that's relieved by the vent. If the vent's clogged ,(or has strong wind creating a vacuum) the system will attempt to vent through a fixtures trap, in this case your toilet. The suction will pull the water in the bowl out and that's what you see surging up and down. I can't pin-point the exact problem since both causes gve the same symptoms. I live on the Gulf Coast and when we have a storm roll in off the Gulf the wind will cause the water in the bowl to jump up and down. If you're not in a windy location then my guess would be a blocked vent, Good luck, Tom.