I am helping someone with this problem and have only had it described to me, along with a layout of the house.
A one story, concrete slab house, five years old is experiencing the problem. Infrequently when the kitchen faucet is turned on there is air discharge and hammering from both the cold and hot faucets. If the faucet is turned on slowly and then one of the two bathroom sinks is turned on, then return to the kitchen faucet and turn on full, no air and no hammering.
Just recently the washer on one of the two faucet handles was replaced as the water would not turn off.

Not having 'laid hands' or eyes on it yet I cannot describe fully the layout. I have been told that there is no increase whatsoever in the water bill and no detectable leak anywhere in the house. I'm wondering how the air is getting into the line as no other water supply in the house does this, or so I'm told.
Is there a way for a faulty kitchen sink faucet to allow for this? The person is not remiss to replace the entire faucet so that would not be an issue.

Thank you in advance.

I am helping someone with this problem and have only had it described to me, along with a layout of the house.
A one story, concrete slab house, five years old is experiencing the problem. Infrequently when the kitchen faucet is turned on there is air discharge and hammering from both the cold and hot faucets. If the faucet is turned on slowly and then one of the two bathroom sinks is turned on, then return to the kitchen faucet and turn on full, no air and no hammering.
Just recently the washer on one of the two faucet handles was replaced as the water would not turn off.

Not having 'laid hands' or eyes on it yet I cannot describe fully the layout. I have been told that there is no increase whatsoever in the water bill and no detectable leak anywhere in the house. I'm wondering how the air is getting into the line as no other water supply in the house does this, or so I'm told.
Is there a way for a faulty kitchen sink faucet to allow for this? The person is not remiss to replace the entire faucet so that would not be an issue.

Thank you in advance.


Sounds like a mystery to me. If you were on a pump system I might blame that but since you mention a water bill that means a closed system. The pipes and valves/faucets are under pressure and a leak would let water out but not let air in. I know of no faucet that could interject air into the system and the fact that it only happens occasionally just makes it harder to track down. Anything else tied back into the water system? Hot water heating? Sprinkler system? Ya got me sport! I haven't a clue. Tommy, Lab, Flickit, Durrel? Any ideas? Tom

Sounds like a mystery to me. If you were on a pump system I might blame that but since you mention a water bill that means a closed system. The pipes and valves/faucets are under pressure and a leak would let water out but not let air in. I know of no faucet that could interject air into the system and the fact that it only happens occasionally just makes it harder to track down. Anything else tied back into the water system? Hot water heating? Sprinkler system? Ya got me sport! I haven't a clue. Tommy, Lab, Flickit, Durrel? Any ideas?? Tom
Giving your utility a call to find out whether they have been doing any work that may cause air to enter the main or know of any one else nearby with a similar problem? Given the low rate of occurrence of this phenomenon and the amount of air leaking out when it does occur it seems like a worthwhile call. The point is to be open-minded about the root cause since logic evidently rules out an in house cause for the time being.

I did not actually have to go over to the house. Turns out that a new sub division is being 'installed' up the road. Looks like they were working on the water system and that's where the air was coming from, especially since the air in the line is no longer occurring.

Thank you both for the advice and quick responses.

Paul