The power to flush away your heating problems
How scale and corrosion can hit your pocket
Just as the performance of a racing car is heavily influenced by the fuel that it burns, the efficiency of a central heating system is heavily influenced by the quality of the water circulating within it.
The way in which we gauge the efficiency of our boilers in this country is known as a SEDBUK RATING (seasonal efficiency domestic boilers United Kingdom) this rating measures the average boiler performance over a 12month period. The most efficient boilers are given a band A rating and the oldest or least efficient a band G rating.
The problem with Scale
In central heating systems scaling is caused by deposition of lime, or black iron oxide corrosion debris.
Lime scale itself is calcium carbonate, but sometimes Lime scale deposits can contain sludge debris which has become mixed with the scale. In soft water areas the deposits can be all sludge.
Modern boilers have very high heat transfer rates achieved by modern fabricated heat exchangers, they are less tolerant of scale deposition. Initially noise is generated due to localised boiling but as the scale deposits build up the temperature increases and results in overheating causing the boilers safety devices to lock out.
Scale is also a problem because it:
- Reduces efficiency of system increasing fuel bills & CO2 emissions
- Increases noise
- Can cause thermal stress to the metal components of the system
Boiler noise is usually caused by localised overheating of the recirculating water leading to steam generation and can be extremely irritating. Hot spots can cause steam to form and the noise is caused by thousands of tiny bubbles breaking away from the heat exchanger. If the bubbles are large then this can cause loud banging on the boiler.
This scale is formed by the removal of calcium carbonate from the primary water under the action of heat.