Limescale builds up on the heat exchangers, creating a significant insulation which substantially reduces the capacity of the heat exchangers to heat the water; expending more energy to compensate for the mineral buildup that encapsulates them. Just a small coating of limescale of 1.6mm (.06") on a heat exchanger in a boiler system can reduce its efficiency by an average of 11%. As the scale increases, the efficiency losses rise dramatically.
| Scale Thickness (mm) -> | 0.4 | 0.8 | 1.6 | 3.2 | 4.8 | 6.4 | 9.6 | 12.7 | 15.9 | 19.1 |
| Gallons of Oil Wasted Per 1,000 | 40 | 70 | 110 | 180 | 270 | 380 | 480 | 600 | 740 | 900 |
| Pounds of Coal Wasted Per Ton | 80 | 140 | 220 | 360 | 540 | 760 | 960 | 1,200 | 1,400 | 1,800 |
| Gas Wasted Per 1,000 Cubic Feet | 40 | 70 | 110 | 180 | 270 | 380 | 480 | 600 | 740 | 900 |
| Average Efficiency Loss | 4% | 7% | 11% | 18% | 27% | 38% | 48% | 60% | 74% | 90% |
| Scale Thickness (mm) -> | 0.5 | 1 | 2 | 4 | 6 | 8 | 10 | 12.7 |
| Decrease in Condensing Capacity | 5% | 9% | 17% | 23% | 29% | 34% | 50% | 56% |
| Increase in Condensing Temp (oC) | 0.4 | 0.8 | 1.6 | 3.2 | 4.8 | 6.4 | 8 | 10 |
| Increase in Energy Required | 5.8% | 10.6% | 20.2% | 29.4% | 35.6% | 46.8% | 66% | 76% |
A New Mexico State University reports that by reducing and preventing limescale build-up on pipes and appliances, households could experience a 30% savings in energy costs which averages approximately over $1,100 a year.
Components in appliances such as gauges, valves, pumps and thermostats when damaged by limescale, can cause incorrect readings that result in overall poor performance and overheating unnecessarily.