Red Seal Plumbing Practice Exam

What is the main function of a low water cut-off (LWCO) on a boiler?

1. To regulate water temperature

2. To prevent the main burner from firing if water levels are low

3. To control water flow

4. To detect leaks

The correct answer is: To prevent the main burner from firing if water levels are low

A low water cut-off (LWCO) on a boiler is a safety device that is designed to prevent the main burner from firing if the water levels inside the boiler drop too low. This is important because low water levels can cause damage to a boiler and potentially create a safety hazard. Choosing option B is the best answer because it directly addresses the main function of a low water cut-off. Options A, C, and D are incorrect because they do not accurately reflect the primary purpose of an LWCO. Option A is incorrect because regulating water temperature is not the main function of an LWCO, although it may help to control the temperature indirectly. Option C is incorrect because controlling water flow is generally the role of a separate water flow control device, such as a pump. Option D is incorrect because detecting leaks is not the primary purpose of an LWCO, although it may help to identify a