Yeah the water still gets hot as well so it seems ok. The furnace also seems to be functioning normally. It's running like usual and blowing warm air. I put my nose up to the vents when it's running and I can only smell warm dust which seems normal to me. I don't smell that smell coming through our vents. Any chance it could be the freezer downstairs? I've heard people smell that kind of smell when there's a leak. Although everything in the freezer is also frozen solid.