Hotplate O' Rings every three years need to be replaced. The screw for the metal plates removal is of special tip pattern. Also if the ignite does not turn on, the ignition package of the hotplate needs to be replaced too. However some times otplate glass cover is glued to the metal base. In this case removing the glass top cover might crack the hotplate. In such a case use of the gas lighter was recommended by the gas fitter. Engineer Hojjat Jafari replaced the O' Rings of the hotplate as they were all worn out.