Hot surface igniters are manufactured in which of the following voltages?

Hot surface igniters are commonly manufactured in 24 volts and 120 volts. The reason these voltages are utilized is primarily due to safety and efficiency considerations in commercial and residential applications.

A 24-volt igniter is often found in systems designed for low voltage operation, which reduces the risk of electric shock and allows for more energy-efficient operation. This lower voltage is also compatible with various control systems used in gas appliances. On the other hand, a 120-volt igniter offers robust starting capabilities while being suitable for a wide range of appliances due to the prevalence of 120-volt electrical systems in many regions.

Using these specific voltages ensures that the igniters can effectively ignite gas burners while maintaining safety standards and being compatible with the existing electrical infrastructure. Other voltage options presented in the question, such as 12v, 48v, 36v, or 240v, are less common for this type of application, which is why they do not fit the standard manufacturing practices for hot surface igniters.