We purchased a house recently and our bathroom has a drain in the floor that gives off a smell, what we can do to eliminate the smell.

Is it a simple floor drain? Sometimes they smell because they haven't been used. Pour a few cups of water down the drain to see if that stops the problem. Many times the traps get dry and allow sewer gas to come back up. If that doesn't fix it, you might consult a plumber. Have you considered any San Jose plumbers?

Yes, bad smell occurs because it has not been used for a long time. Put some cleaner liquid it will remove the bad smell and if the smell is still coming than call the plumber for that.

Thanks guys but I already have tried it. It didn't work. My husband took the cover off and found cylindrical plastic box with 2” plastic pipe in the middle. Water is flowing into the 2” pipe but the smell is still there.

Is there plastic cup that slips over 2” pipe? Similar to the one in the picture below. They sell several different looking models here but the principal is the same. If not, buy one and it should do the trick.
Adam

Thanks guys
You got this one right. It was missing plastic piece that caused all the trouble. I really want to thank you for answering and helping us with this.

I'm glad we could help at least a bit. This is very common problem with floor and shower drains in this area.
Those plastic made traps are not designed properly and could not pass plumbing inspection where you are from. Plumbers are using those things here, simply because there are no other p traps available.
If you are remodeling your home and or installing new plumbing lines have your plumber use 3 abs or PVC elbows glued together rather than those suspicious boxes.