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How often should a tank water heater be flushed?
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What’s a sensible flushing interval for a tank-style water heater when the water is hard or known to carry sediment? I’m curious how much the answer depends on water conditions, the heater’s age, and the manufacturer’s guidance, and what signs actually point to sediment buildup rather than just normal aging.
I’ve also heard that a drain valve can clog or fail to reseal during a flush. If it won’t flow freely or starts leaking, is it best to stop and call a plumber rather than keep working at it? I’d be interested in how you weigh routine flushing against leaving an older or questionable valve undisturbed.
2 replies
- Popping or rumbling during a heating cycle can point toward sediment at the tank bottom. A drop in usable hot-water capacity can fit too, since sediment may reduce the space available for water and interfere with heat transfer.
- Slower recovery by itself is less telling; compare it with the heater’s past performance before blaming sediment. Gradual changes can also come with normal aging.
Use the heater’s manual as the starting point for the flushing interval, including whether hard or sediment-heavy water calls for more frequent maintenance. On an older heater with a questionable drain valve, weigh the maintenance benefit against the chance the valve won’t reseal. If it won’t flow freely or begins leaking, stop rather than forcing it and get a plumber’s assessment.
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