New kitchen faucet pulsates when water is on.

[patagriff]

I just put in a new kitchen faucet. It's the type with a handle for hot and one for cold, but the water flows through a single neck. It was fine for a few days, but when I was doing dishes yesterday, the water stream began pulsating like a shower massage or water pik. The faster I turn on the water, the quicker the pulsations. It's almost like there is a propeller or impeller of some sort causing this.

I thought maybe it is air trapped in the lines, but I don't have any good evidence for this hunch. What's going on?

[EIFSpector]

The first thing I would check is the supply valves, and/or any adjustment controls/valves on the faucet itself. Are they open all the way? If all else fails, call the contact phone number of the manufacturer.

[Speedbump]

Do you have a well or are you on city water?

[Redwood]

It sounds like one of the supply valves has a loose washer. Are you getting a jackhammering noise as well?

[patagriff]

I am on city water. I should mention that I also recently installed a new water heater and it has this funky air-tank attached to it on top, called a thermal-expansion tank. I guess it's to keep undue pressure from building up inside the tank if it begins heating completely full of water. Could this be the source, since the heater is less that ten feet from the kitchen faucett?

[Redwood]

No, If anything it would help to dampen the pulsations.

Do they occur with just the hot on?

Or,

Just the cold on?

Or, Only with both on?

Is there a jackhammering sound?

Does your faucet have a side sprayer?

Does it happen when using the side spray?

[patagriff]

It happens with hot or cold, and with both running the pulsations just intensify. Yes, it has a side sprayer. The water does not pulsate when it's coming out of the side sprayer. I like the way you are methodically leading me to arrive at my own answer. It would seem that it's got something to do with the faucet itself. When the hot water spigot is open half a turn, the pulsation is a rhythmic tick, tick, tick, tick.... open all the way it's tktktktktktktktktktktktktkt.

Obviously, when you squeeze the side sprayer, the same amount of water flows through the hose, because the flow stops from the faucet completely. However, it doesn't pulse coming out of the sprayer.

I'm taken this freakin' faucet back to Home Despot where I got it. I'll be sure to let you know ultimately what caused the problem. Thanks for your correspondence.

[Redwood]

The diverter valve for the side spray is causing the pulsations....

The next question would have been if the hose or, sprayer was leaking...

But hopefully it isn't on your new faucet....