Let's start at the top of the tank. Examine the top of the tank for any signs of rust or corrosion. Most rust and corrosion will happen around the two tube that extend upward from the top of the tank. Those tubes are called, pipe "nipples." If those nipples have been connected to certain types of metal, breakdown of the metal can occur. The result may be rust or corrosion. It's important to call Affordable Service immediately if you see this type of breakdown of the metal surface. Why? It's what you don't see-- the rust and corrosion on the inside of the pipe nipple. The result? Major failure of the pipe, leading to flooding.
Let's move to the tank itself. In our area, the water is very "hard"-- meaning that the pH and alkalinity is high. The high pH can lead to early corrosion and buildup of calcium and magnesium in the bottom of the tank. That corrosion can lead to sediment that lies at the bottom of the tank. That sediment can actually come between the flame that heats the water and the water itself. One tell-tale sign is a knocking or pinging sound coming from the water tank. If you're comfortable, you can drain the water heater every six months. However, you may wish to contact Affordable for complete service and we can be on the look-out for other issues, as well.
Moving to the bottom of the tank-- look for the same corrosion issues that you were looking for at the top of the tank. The same problems can exist at the bottom of the tank as well. Also, think about the thermostat. Have you had to increase the temperature of the water heater lately? If you have, sediment could have collected at the bottom of the tank, making it heat inefficiently.
Whatever the case, check your water heater frequently. And, as always, contact Affordable Service Plumbing and HVAC for an evaluation or timely repairs.