I have an odd noise problem in my hot water line. It happens when my Furnace is running. I can place my hand around the hot water line right as it exits the water heater and can feel the pipe vibrate and make sounds. This problem started during this seasons heating period about 3 months ago and I have yet to figure out the source of the noises. The noise is like something is turning a faucet on and off VERY quickly .... rapidfire kind of hammering in the pipe.

I just had the water heater replaced due to other issues so that somewhat rules it out...

Because the noise only happens when the furnace is running ... I am now wondering if the humidifier valve might be the problem.. Furnace is a Lennox Pulse 21 and it has a Lennox Helthy Climate WB2-17 Humidifier installed.

The Humidifier is hooked to my Hot Water line. Hummmm I think i will turn off the Humidifier and see....

Anyone else had this or heard of such a thing?