It’s raining right now and I can hear the metalic pings inside the furnace. I know there’s some sort of exhaust pipe for the gas residue to escape, and it has a mesh on top, but doesn’t it seem wrong to have water come in?
Or is that just what happens.
probally isn’t the best for it as it will help corrode the furnace esp. if it is not running. most chimey’s have a cap on top that will prevent this.
Any chimney top or flue vent should have a raised cap over it to prevent water from entering. There’s usually about a 3 inch or more clearance between the top of the vent, and the pitched cap over it, with mesh around the opening to keep animals out.
Water entering a chimney is very bad - over time, either mortar will work it’s way loose, or a metal chimney stack will corrode. In both cases, flue gases and carbon monoxide can enter your living space.
Water entering the flue stack for a gas furnace or water heater will corrode the unit itself, specifically the heat exchanger.
Better get it checked out.
Are you certain that you are not hearing the sound of water hitting the flue pipe? Sometimes it sounds pretty loud, esp. during hail.
A friend of mine was hearing a lot of loud noise coming from her furnace about a month ago. She had it serviced, and the cause of the noise and malfunction turned out to be a bat!