When I turn the hot water on in the bathroom faucet, a clunking noise sounds, and the water stops flowing. If I open the faucet quickly, it happens immediately. If I open the faucet slowly, it takes 20-30 seconds before the noise sounds and the water stops. What causes this and how can it be repaired?
Plumbing – Hot water stops flowing after clunking noise
plumbingwater-heater
Related Solutions
I had this exact scenario in my home and the culprit turned out to be a failing pressure regulator valve. It's typically installed after the shutoff valve where the line enters the home and will probably have a bolt going into the side of the device that would be used to adjust the pressure.
To see if this is the case, go over to the home improvement store and pickup a water pressure gauge that screws onto a garden faucet. Attach the device to any fixture, open the valve and leave it, then go inside and turn on the cold water for 5 seconds, back off, and go back to the gauge to see if it starts climbing as the pipes bang.
You may also notice toilets or other valves leaking in the house if you have an overpressure situation. I ended up replacing several leaking toilet valves and a sink valve because of pressure issues.
Replacing this can be a DIY job if you're comfortable cutting and soldering pipes.
Edit: here's a sample picture
This is most likely due to a partially closed shutoff valve under your sink. Most such valves are designed to stop water but not to just reduce the flow, so if the valve isn't fully opened, it may be partially obstructing the water flow in a way that generates lots of noise/vibration. So check the valves supplying hot water to your sink and make sure they're completely opened.
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Best Answer
Opening the shut off valve 1 additional revolution fixed the problem. It was only open one revolution, which apparently wasn't enough. I can recreate the problem by opening the valve only partially, so it doesn't seem to be a physical blockage. Perhaps air is involved somehow. If anyone can explain why having the valve only partially opened would lead to blockage, I'm curious about potential explanations.