An electric blanket is a comfortable help in cold weather. The blanket has wires on the inside that heat up when the electricity is turned on. Its temperature is controlled by a thermostat found in the blanket's control pad. Repairs are needed when connections come loose, or when the heating wire breaks. Determine the cause of the malfunction before you repair the blanket. Depending on the problem, it can be less expensive and time-consuming to get a new blanket.
Unplug the blanket and check that all the connections are tight. Often, part of the cord or control unit will have been pulled loose. This means that the blanket is not getting enough power and not heating up to temperature. Push all connections back together and use electrical tape to keep the connections tight in the future.
Check that no pins or other metallic objects are stuck in the blanket. This will cause the blanket to shock you when it is turned on. Remove the metal object and sew up the resulting hole.
Use a multimeter to check that the cord is not shorting or defective. Place one multimeter pin onto the plug and the other pin on the opposite end of the cord at the connection point. If the multimeter reads zero when testing continuity, then the cord is fine. If the reading is high, then the cord needs to be replaced.
Replace the fuse in the blanket's control box if it is blown. Power surges can cause overheating or hot spots which will blow the fuse. If the fuse blows repeatedly then the circuit it is plugged into has too many appliances on it. Plug the blanket into a wall socket on another circuit.
Open up the control unit with a screwdriver and look for any loose parts. If the blanket only works on some settings and not others, then the thermostat is broken. Tighten any loose connections within the thermostat.
Replace the heating blanket if you cannot find the problem. In many instances it is less expensive to buy a new heating blanket rather than to fix the old one.