Who should you contact to find out where an awful odor is coming from the closet only when the light is on and from your bathroom when you run the exhaust fan or heater?

Answer 1

Exhaust fan puts the bathroom under negative pressure. The negative pressure will suck/pull sanitary sewer gases into the bathroom from any break in the sewer line or joint. A most likely break occurs where the toilet connects to the sewer pipe where a seal is made via a soft "wax ring". It is common for this seal to break, especially if the toilet is not firmly set, and can wobble or move. Use you nose, close to the toilet base where it sits on the floor- all around-do this with exhaust fan turned on. If the seal is the leak source, you will get a strong "snoot" full of the offending odor. Use same technique at any holes in the walls, such as where water pipes go thru the wall, or electric switches or duplex outlets expose the insideof the wall to the negative pressure. Another possible failure is where the vent piping rots out in the wall. Again, the exhaust fan can suck fumes from the vent pipe hole, into the wall cavity, and into the room via any holes in the wall such as piping,or electric switches or electric outlerts. Can't help with closet when one turns a light on. Are you 100% positive it only occurs AFTER the light is turned on??? In any case, clear the closet out so that there is no smell. Then use your nose to find where the smell is entering the closet. ... or is the source something that is in the closet? Again do a through inventory vie smelling all boxes, clothes, etc. To chase the source, use one nose. Clear out the offending smell; then smell every location in the closet, especially any holes thru the wall. {try the light switxch and the light fixture itself as an example.. Follow you nose. If the smell is septic,ie sewer gas, likely the source is similar to that described for broken,leaking sewer pipes. If the smell is other than septic, try to recognize the smell. - Go from there. A plumber would be the most familiar with such type issues.