What could happen if the burner and ignition sources of a gas furnace are installed too low?

When the burner and ignition sources of a gas furnace are installed too low, it can indeed create a significant risk of gas buildup. This occurs because a lower installation can lead to an improper venting of exhaust gases and insufficient air mixing with the gas. If the flames do not reach the intended combustion area due to their low placement, unburnt gas may accumulate rather than being combusted promptly and efficiently.

Such gas buildup poses a serious safety hazard, creating the potential for explosions or fire if the gas ignites unexpectedly. Additionally, this condition could lead to incomplete combustion, resulting in an increase in harmful emissions such as carbon monoxide, further increasing the risks associated with improperly installed gas appliances.

In contrast, higher placement of the burner allows for better airflow and more effective combustion, contributing to safer operation and improved efficiency. Thus, the correct answer highlights the critical importance of proper installation height for safety in gas furnace operation.