Close the valve to drain the water, remove the faulty cap and install a new cap.
First turn off the faucet to drain the water from the water heater, then use pliers to reach the water level opening, hold the plug in the opening, unscrew it and wind the cotton thread. around the new plug, and finally put the new plug back in place and tighten it with pliers.
Water heaters can be divided into electric water heaters, gas water heaters, solar water heaters, magnetic water heaters, heated water heaters, etc. according to different principles.