What are common output signals from a high-efficiency furnace control board?

High-efficiency furnaces use sophisticated control boards that manage multiple outputs to ensure safe and efficient operation. A key function of these control boards is to regulate various components essential to the ignition and operation of the furnace. The correct choice highlights the output signals from the control board that are crucial for starting and maintaining the furnace’s combustion process.

Specifically, the igniter is responsible for providing the initial heat necessary to ignite the gas. Once the igniter is activated and there is confirmation of successful ignition, the pilot gas valve allows a small amount of gas to flow, creating the flame that will subsequently activate the main gas valve, which controls the flow of gas to the burners for heating. These output signals are essential in ensuring that the furnace operates safely and efficiently, contributing to the high efficiency of the furnace.

Although other choices present important aspects of the furnace operation, they do not directly represent the fundamental outputs that are controlled during the ignition and operation phases of a high-efficiency furnace. For example, while the thermostat and limit control involve signaling for operation, they do not directly execute ignition processes. The fan motor and circulating pump are related to the airflow and distribution of heat but are not involved in the ignition sequence. The combustion air fan and dampers manage airflow