I need some plumbing advice here. We installed a new kitchen sink and faucet and I figured it was a good time to replace the hoses as well. Now every so often the hot water will just stop working (flowing). When it happens a “thunk” sound can be heard like a valve is closing. I disconnect the hot water feed hose, blow air through it, reinstall and it will start working again. I have confirmed there is no issue with the water supply or shut off valve.

I didn't notice there is a plastic valve of some type at each end of the new hoses. Could the hose be defective? Is it possible to install the hoses backwards? Do new faucets come with a safety valve or something built into the mix valve?

-Don

Sounds like you purchased the flood safe type supply tubes. Known to be a nuisance. See this website.
FloodSafe® Automatic Water Shutoff Connectors - New Products - Watts (http://www.watts.com/pages/whatsnew/floodsafe_connectors.asp)

I have to agree with Harold. New faucets do not have any safety valve but it appears you accidentally bought supply hoses with a valve. Valve end of the hose goes to the stop where the supply line comes out of the wall.

I agree with these guys. If you have these supplies, swap them out for regular braided stainless flex lav supplies.

Thanks all! You hit the nail on the head. Probably not the fest fix but I was in a bind so I drilled through the valve and flushed out the hose. No leaks and no more issue.

Ballengerb1 - Why do you say "accidently"? When would one buy these?

You bought the supply line but did not know it had a special shut off valve built into it, you paid extra for something you did not need or know about. I chaulked that up as an accident, unintentional purchase. I have been installing these lines in peoples vacation homes when they request it. Vacation homes have been know to break a toilet fill line and run for months. After awhile I started getting some complaints like yours, sometimes the valve closes during normal use rather than when there is a break.

I chaulked that up as an accident, unintentional purchase. True enough. I wasn't sure what to buy I was just matching the end sizes. And good luck getting someone to assist you at home depot ;-)

Know what you mean. My neighbor works for a box store in the plumbing department but is always asking me for help. At work folks think he's an expert, go figure.