Abstract: A firecheck to be connected to a combustible gas line and including a casing having a gas inlet, a gas outlet and an access opening. A cover plate removably encloses the access opening and a burner screen is located within the casing between the inlet and the outlet and is disposed in communication with the access opening. A control valve is disposed within the casing for controlling the flow of gas through the casing and is movable between an open position and a closed position. The valve is moved to the open position through a manually operated mechanism and is locked in the open position. On release of the locking mechanism the valve is biased to the closed position. Removal of the cover plate from the casing acts to release the locking mechanism to thereby enable the biasing means to move the valve to the closed position.