What is the consequence of a partially closed oil supply valve?

A partially closed oil supply valve restricts the flow of oil to the burner, resulting in reduced oil flow. When there is a limitation in the supply line due to the valve being partially closed, the burner cannot receive the volume of oil needed to operate efficiently. This reduced flow can lead to several issues in the heating system, such as inadequate combustion and lower heat output, which may cause the system to cycle on and off more frequently.

The other options do not accurately reflect the effects of a partially closed oil supply valve. For instance, while increased pressure may occur in a scenario where there is an obstruction or blockage, it is not a direct outcome of the valve being partially closed. Enhanced combustion requires a proper air-to-fuel ratio, which would be compromised by reduced oil flow, making effective combustion difficult. Lower tank temperature is also not a direct consequence, as the tank temperature would depend on other factors such as ambient temperature and usage, rather than the valve position itself. Thus, reduced oil flow is the most accurate consequence of a partially closed oil supply valve.