Pipe "buzz" vs. "chatter"

[LeeMc]

Greetings all -

I am experiencing what I describe as a buzzing noise at either the cold (input) or hot (output) (copper) lines at the tank (water heater). The only change in the system is the addition of a whole house water filtration system at the main which is many "pipe feet" away from the tank. This is a dual canister style system that filters sediment, calcium and phosphates from the supply, and the noise did not immediately start when the filter went on line. Instead, it appeared about a week or so later. The filter is installed after the pressure reg that is set to 55psi. I did have to drain the house lines to solder the copper fittings, and I did not perform a “sequential” bleeding of the air by flushing the faucets closest to the main and then moving sequentially to the furthest. The buzz appears to have no relationship to flow - meaning there is no "chatter" or "hammer" noise when flow is started or stopped. It just “occurs” every 10 to 15 minutes.

Your thoughts and ideas as to cause and solution are appreciated.

[wrench spinner]

Is your water heater electric and if so did you turn it off at the breaker before you drained the whole house down? If not you most likely have fried the elements inside the water heater.

[Devine Plumbing]

The heating elements make a sort of humming noise when they are working. However, every 15 minutes is too frequent. Are you sure the noise is coming from the heater and not the air conditioning, well pump, etc.? What type of heater is it and how old? Turn off the electric to the heater and see if this noise continues, then the well pump, and so on until you figure out just where the noise is coming from.

[boillerman]

This is a good one. It doesn't matter if there's flow or not? The next question is, does it matter if the W/H is in reheating cycle or not? Many W/H's have heat traps built into the pipe nipples at the top of the heater, and B/W for instance uses a little rubber flapper for it. If the heater is heating, I can see expansion maybe causing a vibration on this but it seems a little far fetched if it's every 10 to 15 minutes 24/7. Sounds more like a toilet fill valve with a leaky flapper, and the sound is carrying through the water pipes. Try turning stops off to fixtures one at a time and see if any of those being off make the sound go away.

[boillerman]

Noise carries in water lines. Could still be coming from the filtration or prv.