Basic Troubleshooting Water Heater Guide:

1. Check the Power Supply: As for an electric water heater, ensure it's receiving power. Check the circuit breaker or fuse box to confirm that power is reaching the unit. When it comes to a gas water heater, make sure the pilot light is lit.

2. Inspect the Thermostat: Adjust the thermostat settings to see if that resolves any temperature-related issues. Ensure that both thermostats on electric water heaters are set at the same temperature or it can damage the water heater. Sometimes incorrect settings cause inadequate heating or overheating. 

3. Look for Leaks: Check around the water heater for any signs of leakage, especially around fittings, connections, or the tank itself. If there are visible leaks, it's necessary to call a plumber for further inspection.

4. Flush the Tank: Sediment buildup can affect the efficiency of the water heater. Flushing the tank once or twice a year can help remove sediment and improve its performance.

5. Check for Strange Noises: Unusual noises like banging, rumbling, or popping could mean there is sediment buildup or other issues. Flushing the tank might help in some cases. However, persistent noises might require professional attention.

6. Inspect Water Quality: If the water appears discolored or has a metallic taste, it could indicate corrosion inside the tank. This more than likely means the tank needs to be replaced.

7. Inspect for Condensation: Sometimes, condensation or moisture around the water heater could indicate a small leak or a venting issue. Addressing these issues early can prevent larger problems.

8. Check for Cold Water Supply: If the water heater is producing no hot water, check the cold water supply valve to ensure it's open and supplying water to the tank.

9. Consult the Owner's Manual: Always refer to the manufacturer's instructions and guidelines for troubleshooting specific to your water heater model. It might have specific recommendations or troubleshooting steps.

Remember, while these steps can help address some common issues, always prioritize safety. If you're unsure about any of these steps, if you encounter gas-related issues, or if the problem persists, it's best to call a professional plumber to avoid potential hazards and ensure the problem is properly diagnosed and resolved.