How to Troubleshoot a Kitchen Faucet When the Hot Water Is Not Working

Check the temperature of the water in the bathroom. If the water gets hot, the problem is likely with the faucet; if it's cold, the problem is the water heater.

Check the pilot light on a gas water heater if there is no hot water from any tap. The pilot light is usually located in the lower front area of the water heater, sometimes behind a small door; check your manual if you're not sure of the location. If the pilot is on, you should clearly see a small blue flame. If the pilot is dark and there is no strong gas smell, light the pilot with a long fireplace lighter. If the pilot light doesn't catch or if you smell more than a very subtle amount of gas near the pilot, call the gas company immediately.

Locate the thermostat on your gas or electric water heater. In some cases, there is a thermostat for each room. Verify that the heat is set on the desired temperature for the kitchen sink.

Flush the hot water heater's tank to clear out deposits that may be causing a malfunction. Turn off the gas or electrical power to the water heater. Turn off the valve that allows water to flow from the pipes into the tank. Wait about a half hour for the tank to cool, then attach a garden hose to the tank's drain valve, which looks like a faucet on the side of the water heater. Place the other end of the hose in a sink, then open the drain valve. When the tank is empty, turn on the water valve to allow more water into the tank and out the drain valve to flush out the buildup. Close the drain valve and let the tank re-fill, then turn on the power and, if you have a gas water heater, light the pilot light.

Check the faucet's cartridge and gaskets if the problem is only affecting the kitchen sink. The cartridge, located below the handle, controls the temperature and flow. First turn off the water valve to the sink. To get to the cartridge, pop off the top of the faucet behind the handle with a screwdriver; this is usually a round decorative disc. Loosen the screw inside and lift the handle off.

Remove the cartridge, which is a small tubular piece on a short rod, with needle-nose pliers. Rinse the cartridge off in another sink. If it appears damaged, purchase a replacement cartridge at a hardware store. Check the gaskets and O-rings inside the faucet; replace any that appear deteriorated. Replace the cartridge and reassemble the faucet handle. Turn on the water valve, then the faucet to check the water temperature.