Odor from bathroom sink

[Novatech]

Hello All.

Moved into a new home October 1st. It is newer construction (2004) with ABS and PEX. There is a sewer odor originating from the bathroom sink drain in the master ensuite. There is also a toilet, shower unit, and soaker tub in this area. None of the fixtures are clogged. I cleaned out the sink drain and poured drain-0 to see if that would eliminate the odor but it still remains. I inspected the plumbing underneath the sink and it appears that the sink is tied into the drain of another fixture (I'm assuming the shower) before it runs into the wall cavity and into the roof stack. I have included a pic.

Just wondering how this can be repaired. Any help would be appreciated.

Thanks.

 

[journeyman]

it is possible that if you have just a shower unit in the bathroom that the smell is actually coming from shower drain. Scum collects around rim of shower drain. Pull grid off and see what top of drain looks like. If there is scum you can clean with a screw driver and run water. Other thing could be if you have a metal pop-up assembly to sink that the metal is starting to rot which will give a foul smell. Also check to see if toilet is sealed at base. If not air can get between toilet and wax seal and cause a foul odor. Also the overflow on sink could have scum in it causing an odor. fill sink up with water and pour in some simple green to help eat away some of the scum.