A propane tank that is not discharging gas when the valve is open can be clogged. Because the valve has a place where the hose can be connected, it is not uncommon for some debris to get into the valve and clog the release of the propane.
Inspect the valve on the propane tank for any dirt or debris that can be clogging the release valve.
The valve on top of the propane tank screws on and off. The screw assembly on the valve tightens down to shut off the flow of propane to the hose and unscrews to open the valve.
If the screw handle is worn or stripped, it cannot be unscrewed to allow propane to flow freely. The end of the screw handle can break internally, allowing the shutoff valve to remain closed.
The entire valve on top of the tank must be replaced if this occurs.
The service valve is designed to release propane only when a hose connection is inserted into the valve and tightened. You can actually unscrew the service valve without a hose being connected and the valve will not release any propane.
The pressure plate that engages and releases propane can be damaged. If the pressure plate is damaged and a hose connection is installed, but no propane is discharged, the service valve requires replacement.
Another common problem with a propane tank that is not discharging propane can be found in the supply line or hose. If the hose is damaged or the supply line kinked, it prevents propane from discharging into the appliance or furnace.
Replacing the hose or supply line is the only correction for this problem.
The regulator on the propane tank can freeze and block the discharge of propane from the tank. A frozen regulator is created when the gas appliance sits idle for long periods of time.
If the gas appliance is being used, the liquid propane boils, which prevents the regulator from freezing. If you plan on not using the gas appliance for long periods of time, it is best to shut off the service valve.
It may be obvious to some propane users, but many times users don't realize that the tank is empty.