Loud buzzing noise from pipes after valve install

[Donatello]

My dad installed a mixing valve that allows metered hot water to mix with the cold water so the toilet doesn't drip due to condensation build-up. With the house (and toilet) very warm add in the cold well water, there is a lot of condensation that puddles the floor... The only issue now is the annoying buzzing noise (from the pipes) you hear every time the toilet is flushed until the tank is refilled and the noise stops. I tried adjusting the valve, but still makes buzzing... None of the pipes are touching. No air in the system. Anybody ever have an issue like this ???

 

[Reedwalker]

Got any pictures of this set up?

My first inclination is to tell you to add a hammer arrestor. But I'm not 100% sure that this will solve your problem yet.

 

[havasu]

Just an educated guess, but I'm wondering if the mixing valve itself is the "root" of the problem? Was it designed to be used for this purpose? Could it have a defective diaphram?

This may take some time, but I would eliminate the mixer and try pure hot water. If the sound is gone, you will know it was the mixing valve that caused the problem. If the sound continues, then I would be looking at the pipes themselves and possibly install a hammer arrestor as Reed recommended.

Also if possible, could you take a picture of this mixing valve?

 

[phishfood]

I have run into ballcocks valves that will make noise as they fill the toilet tank, but that should not have been brought on by the installation of the mixing valve.

Edit: After a bit more thought, I am wondering if the higher temperature of the incoming water is changing the harmonics of the water flow through the ballcock, and causing noise. If it is possible to adjust the flow rate through the ballcock to fill the tank slower, you might try that.

 

[Donatello]

I put a couple pics up top.... The valve shown is a replacement for a similar valve that was seized.

 

[Reedwalker]

The installation looks nice and clean. Your Dad did a nice job!

I'm not familiar with this particular valve but it looks like its the most simple mixing valve available. Meaning it does not have integrated check valves.

You definitely need to install spring loaded check valves on each side before the mixing valve. This will eliminate the possibility of "backflow" through your system. As it is right now, every time you run only cold water, the pressure on the hot side is slightly higher. Allowing hot water into the cold water system. These simple checks will stop that. Its possible that they will sovle the problem.

Like Phish said next would be the ballcock. I am a fan of fluidmaster. Inexpensive and reliable. Easy to swap out.

If this fails to solve your problem then the hammer arrestors are the last resort.

Good Luck! Let us know how it turns out.

 

[Mr_David]

I agree with Reedwalker.
If you have this type of a ballcock it can develop a harmonic tone and resonate the copper pipes. 400a fluidmasters are great. We use the Pro45B.