The lift pump is still woking just fine as far as I can tell. What happens is that every time it runs the water spots in each toilet become much smaller and some of the sink and bathtub J-traps are sucked dry and sewer gas is quickly noticed. Why is the pump pulling a vacuum within the septic system when it runs? We noticed the odor problem for several weeks before the association with the running lift pump was recognized.

With all the cold and snow lately in WI my first guess would be a frozen vent pipe.



Edited 1 times.

For some reason the vents are not working, so the system cannot "suck" air in to replace the water being pumped out. Therefore, the only place it can get air is by sucking the water out of the traps.

in the olden days:

vents through the roof were 4" diameter pipe and 48" above the roof line minimum to avoid PRECISELY the issue of freeze up

hj, please let's NOT start a debate on the 'specifics' - this is about the principle

==============================================

"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

massachusetts code says the VTR must be 18 to 24 inches above the roof. it is illegal in massachusetts to put 4 feet thru the roof.

12" minimum above the roof line here. If its within 10 ' horizontal of an opening window we can extend up to 10' if we use guide wires to steady the vent. I've never saw that one, its just an option if worse comes to worse.