Hard water carries dissolved minerals that drop out as scale when the water is heated. In a tank that scale settles on the bottom, between the burner and the water, so the burner has to run longer to deliver the same hot water. In a tankless unit it coats the heat exchanger passages and restricts flow. Either way it costs efficiency first and lifespan second.
How do you know scale is building?
The symptoms arrive gradually, which is why they get ignored until the unit fails.
- Popping or rumbling from the tank as water boils under the sediment layer
- Hot water running out sooner than it used to
- Longer recovery between showers
- A tankless unit throwing flow or temperature error codes
- Reduced hot water pressure at fixtures
What slows it down?
Flushing a tank annually removes sediment before it insulates the burner. Descaling a tankless unit annually clears the exchanger. Both are routine maintenance, and both are commonly skipped until there is a problem.
Lowering the thermostat slightly also helps, because scale drops out faster at higher temperatures. Keep it at or above 60C for safety reasons though, since Legionella risk rises below that.
We flush tanks and descale tankless units as routine maintenance across the Fraser Valley, and we will tell you honestly when a tank is too far gone to be worth flushing.
Book Water Heater Maintenance
A flush or descale costs a fraction of an early replacement.