Air coming out of hot water lines only
Trapped air in hot water lines is often caused by a failing or recently replaced water heater that generates gas or allows air to enter the tank. Running the taps only offers a temporary fix because the underlying source of the air inside the system hasn't been resolved.
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.
Air coming out of hot water lines only
- 1Keeping the water dripping when it is coldDid this help you?
- 2Checking if the valve underneath is all the way onDid this help you?
- 3Running the tub and sink on hot for five or so minutes to flush out air.Did 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.
“I had my hot water heater replaced a week ago, and the hot water is still milky and has a sort of sour fruit smell to it.”source ↗
“My friend advised me to run my tub and sink on hot for five or so minutes to flush out the air, but this only worked for a few hours tops before returning again.”source ↗
“It’s only happening with hot water, it’s an older house and I’m not sure when the water heater was last replaced”source ↗
“I’m just trying to figure out why bc the air isn’t going away”source ↗
“It’s with all the sinks”source ↗
Where this came up
People with this problem also raised
- 5Why does it take so long for hot water to reach distant bathrooms?
- 15Why is there water on the floor around my new water heater?
- 9Water spitting out of pump vent pipe
- 4Why is my shower water bubbling and making a pulsing sound?
- 8Why is my plumbing or AC making bubbling noises?
- 3Why are my cold taps running tepid after a water heater service?