What is the maximum control voltage allowed on a boiler?

In the context of boiler operation, the maximum control voltage typically used is 120 volts. Control circuits in many heating applications, including boilers, are commonly designed to operate at low voltage for safety and reliability. This is especially relevant in residential and commercial heating systems, where lower voltage levels help reduce the risk of electrical shock and ensure better compatibility with various components such as relays, thermostats, and safety devices.

The 150V option does not align with standard practices in HVAC systems. While there might be systems with higher voltages, they are not typical for residential boilers, which prioritize safety and user-friendliness. Choosing a voltage too high for control circuits can lead to equipment damage or unsafe operating conditions. Therefore, understanding that the safe operational range focuses on 120V allows technicians to effectively manage and troubleshoot boiler systems.