Low hot water pressure at only one faucet
When low hot water pressure affects just a single faucet while the rest of the house has normal flow, the issue is isolated to that specific fixture rather than the water heater. It is typically caused by a clogged aerator, a partially closed supply valve, or a blocked cartridge under that specific handle.
What the numbers show
Counted from the threads quoted below. How we count
- The most recent one is from October 2026.
- This comes up 17.5× more often in r/Plumbing than across the site as a whole.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1Checking the aerator to see if it is clogged2 people mentionedDid this help you?
- 2Disconnecting the hot side supply line and spraying it into a bucket to test pressureDid this help you?
- 3Turning off the angle stop and inspecting the supply line for clogsDid this help you?
- 4Checking or replacing the faucet cartridge and angle stop sealsDid this help you?
- 5Hiring a plumberDid this help you?
- 6Unhooking and cleaning out the pipes, and checking inside the faucet for clogsDid this help you?
- 7Replace the tap aeratorDid this help you?
- 8Disconnect the supply hose from the faucet and test flow into a bucketDid this help you?
- 9Rinse out or check the faucet aerator for gunk and debrisDid this help you?
- 10Checking if the valve under the sink is completely openDid this help you?
- 11verifying the shutoff valves are fully openDid this help you?
- 12disconnecting supply lines to test pressure directly from the wall valvesDid this help you?
- 13shooting compressed air through the faucet to dislodge debrisDid this help you?
- 14Check for and clean out sediment in the aeratorDid this help you?
- 15Make sure the water line shut-off valves are fully openDid this help you?
- 16Disconnect the water line from the faucet to test the pressure directlyDid this help you?
- 17Replacing the faucet cartridgeDid this help you?
- 18Replacing the downspoutDid this help you?
- 19Flushing the line and faucet to clear debrisDid this help you?
- 20Replacing the pressure-balancing valveDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Does anybody know the fix for this??”source ↗
“This only affects one faucet. The rest of the plumbing has the same pressure for hot and cold.”source ↗
“This only affects one faucet. Would that still be a water heater issue?”source ↗
“It worked for a few days, but now it’s back to doing this again.”source ↗
“I’ve been away for the summer and come back home to find that my upstairs bathroom tap has low water pressure.”source ↗
“I have checked all the other taps and showers in the house and they are all working normally.”source ↗
“I have tried hot and cold and the tap has low pressure on both.”source ↗
“The cold water has great pressure. The hot water was a dribble.”source ↗
“Then it came out strong for a day. It has gone back to a low stream.”source ↗
“I have a double vanity and one of the two faucets is losing water pressure.”source ↗
“I’ve removed the aerator to see if it’s clogged, and I’ve checked that the shutoff valves under the sink are all the way on.”source ↗
“The water stream is exactly the same whether it’s only cold, only hot, or both.”source ↗
“I've got a Tuscany 673-6000 single handle shower that has good pressure on the cold side but drops significantly on the hot side.”source ↗
“I've replaced the cartridge (and the downspout) and it got marginally better but still drastically different pressure on the hot vs the cold.”source ↗
“faucet has little to no pressure on the hot side but cold side is fine.”source ↗
“There’s low water pressure in the bathroom faucet how do I fix it?”source ↗
“The faucet is turned all the way in and there’s little bits of water coming out.”source ↗
“It has been when I first moved in but yeah. The other bathroom is fine, just this one in particular.”source ↗
Where this came up
People with this problem also raised
- 3Why does water pressure drop when another faucet turns on?
- 12Why is there no water pressure after changing a faucet?
- 3Why are all my faucets sputtering on hot and cold water?
- 8Why is only one tap losing hot water?
- 4Why does water flow drop drastically with normal pressure?
- 3Why does my hot water stop when the sprinklers run?