If the regulator shutoff or main CO2 tank valve is closed, what should be done?

When the regulator shutoff or main CO2 tank valve is closed, the appropriate response is to turn the regulator shutoff back on. This action allows CO2 to flow from the tank to the system again, enabling the proper carbonation and dispensing of the beer. It's an essential step to restore functionality and ensure that the beverage is served at the desired pressure and carbonation level.

While there may be other considerations regarding leak checks or tank replacement under different circumstances, the immediate action to regain control over the system flow is to ensure that the regulator shutoff is opened. This restores the flow of CO2 and addresses the issue of the system being unable to dispense beer correctly due to a lack of pressure.