I have a Watts DET-5 Potable water expansion tank. The unit was installed 4 years ago, about 36" before the gas water heater. Recently I notice the water heater pressure relief valve began to have an occasional discharge. And the drain valve on the water heater developed a slight drip. I took a pressure reading of the expansion tank, it was 0.
The tank felt like it might be filled with water. Can I recharge the tank with a bicycle pump or should I replace it? Do I need to drain the expansion tank?