Gas Fitter Practice Test

Which of the following is used to de-lime a hot water tank?

1. Ammonia solution

2. Bromide acid

3. Muriatic acid

4. Tri-sodium phosphate

The correct answer is: Muriatic acid

Muriatic acid, which is a diluted form of hydrochloric acid, is effectively used to de-lime a hot water tank due to its strong acidic properties. Over time, mineral deposits such as calcium and magnesium can build up inside hot water tanks, causing inefficiencies and potentially damaging the tank. Muriatic acid reacts with these mineral deposits, helping to dissolve and remove the scale buildup. This method of maintenance is crucial because it restores the efficiency of the hot water tank, allowing it to operate effectively and prolonging its lifespan. When using muriatic acid, safety precautions should be taken due to its corrosive nature, and the area should be well-ventilated. The other substances listed are not typically used for this purpose. For instance, ammonia solution is primarily used for cleaning and does not effectively remove lime scale. Bromide acid isn’t commonly referenced for this application, and tri-sodium phosphate is typically employed for cleaning and degreasing rather than for de-liming purposes. Hence, muriatic acid stands out as the most effective and commonly recognized choice for de-liming hot water tanks.