What Hard Water Does to Your Plumbing
Scale settles wherever water is heated, aerated or slowed. It coats heating elements until they stop transferring heat, blocks aerators until flow halves, roughens the ceramic discs inside tap cartridges until they drip, and narrows old galvanised pipe from the inside.
Where it lands first
Heat drives it out of solution, so the water heater sees it before anything else. A coated element has to run longer to reach the same temperature, which costs electricity quietly for years and eventually burns the element out. The next casualties are the small apertures. Aerators at the tap outlet, shower heads, the tiny ports inside a thermostatic cartridge that has to move to control temperature.
The faults it hides behind
A dripping tap is usually described as a worn washer. Often the real cause is scale that roughened the ceramic disc until it could no longer seat. A shower that swings between hot and cold is usually described as a pressure problem. Often the wax element inside the thermostatic valve is seized in scale. Treating the symptom replaces the part. Treating the cause means descaling and renewing together.
What actually helps
Flushing a water heater periodically removes sediment before it insulates the element. Cleaning aerators takes ten minutes and restores flow that people assume is a mains problem. Whole property softening changes the chemistry rather than the symptoms, and it is a decision about cost and maintenance rather than an obvious yes. What does not help is fitting a bigger pump to push water through a scaled pipe.
Common Questions
Is hard water dangerous to drink?
Hardness is a matter of dissolved minerals, not safety. It is a plumbing problem and an appliance problem rather than a health one. Questions about drinking water quality belong with your water authority, not a plumber.
Will a water softener fix my low pressure?
Not retrospectively. Softening prevents future scale. It does not remove the scale already narrowing an old galvanised run, and that pipe stays narrow until it is replaced.
How often should a water heater be flushed?
Periodically, and more often in hard water. The useful signal is performance. A heater taking noticeably longer to recover than it used to is telling you the element is coated.
Last reviewed
