This house is 2 years old and when it is damp outside we get a odor in the shower in the master bedroom only. The whirlpool tube, and sink are OK in this room. We have added an additional vent on the shower/sinks and we are still getting this odor only when it is damp. This system is on a spetic tank, but everything else in the house drains good and there is no odor. (Total vents out roof on this system is 4) Also, traps have been checked and are OK. Any suggestions?

Most bad odors in bathroom drains come from rotting hair mixed with grease from the soap. Try this. Remove the two screws holding the strainer. (TIP; put the screws in the soap dish before they get lost down the drain.) Shine a light down there and with a bent coathanger fish out any hair that may be hiding down there. Then pour a 1/2 gal. of bleach down into the trap and let it set over night. Next morning flush the mess down with 2 large pans of boiling water, (this is important). The bleach will dissolve the hair and make it slippery and the boiling water will melt the grease and get the mess out of your drain. Smell better now? Cheers TOM

Excellent advice Tom

Tom