Hot Water Line Noises

[FordBlueChevyRed]

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?

[jadnashua]

Humidifier water valves are typically solenoids, and those do turn on/off very quickly. That can make noises. They do make a water hammer arrestor that could be installed in that line which should solve that. It may just be that you need to anchor the water line better or move it away from something that it is banging into when it jumps with the water shutting off.

[FordBlueChevyRed]

Jim,
The noise is not just a one time hammer sound but a persistent, random length, random time, machine gun series, that lasts 2,3,4 seconds at times and does this maybe for a half hour at a time then it goes away. I did turn off the humidifier last night and there was no noise this morning. I will now have to figure out if the control box (where you set the humidity level required) or the solenoid, or the wiring between the two is at fault.
I know the system can be noise free as it is because this noise just started this year and hasn't ever been noisy in the last 14 years. With that said, I don't think i need the anti water hammer device you mentioned, at least not at this point in the problem solving.

Anyway, Thank you kindly for your response and advice. It is always good to have an extra input when trying to solve those oddball problems.

Kim

[jadnashua]

Based on the fact it stops when you turned off the humidifier, it could be the solenoid valve, or the control to it. Or, it could be a loose connection. Probably not easy to see if you put a standard multimeter on it unless it has a quick reaction bar graph.

[carol efaw]

We did a complete re-plumb of the entire house. Whenever we turn the hot water on in the bathrooms or the washer is running, we hear, what sounds like water dripping somewhere in the wall. The contractor says it's just the pipes making noises when it changes temperature from cold to hot. Never had these problems before in our last house with copper plumbing. Any ideas?

[jadnashua]

What kind of pipe did you have installed? Something like cpvc expands and contracts LOTS more than copper, and as it changes length, if it is not supported properly and provision made for it, it can make what sounds like ticking or clicking sounds as it jumps in the clamps or through holes if they're tight.

[Terry]

if it is not supported properly and provision made for it

They can make those noises when they are properly supported too. Heated pipes expand and contract.