In need of some expert advice again. Could you guys tell me what this thing is inline in the exhaust from the gas furnace in my house? The furnace is in the crawl space and the component in question is in the top left hand corner of 1st pic.
Water (condensation probably) drips from it during the heating season. The furnace seems to work fine and it was ckd out by a pro about 6 months ago; he told me what it was but now I don't remember.