We live in a rural area and have a submersible pump in our well. We noticed just a couple of days ago that we started getting air in our pipes (hot and cold) and sediment through faucets, etc. I went down to the tank room and noted that the pipes sounded like water was flowing, as when a faucet is turned on, although none were. Also, the tank will fill, then as soon as it clicks off, the pipe noise starts again, and the pressure starts to drop in the tank. No faucets, etc are on at all when this happens. I don’t find any evidence of leaks anywhere in the house. Could the water be siphoning back into the well, causing the noise? If so, does that mean replacing the pump? Thanks for any help/advice.
The only way an expansion tank can drain is for air behind the bladder to push it out. If your tank does not drain completely than it does not have enough air in it to displace the water inside. And the bladder may have a hole in it. If this is the case buy a new tank.
To drain an expansion tank
First you need to drain the tank as far as it can go by itself. Next using a bicycle tire pump up the tank only until the water begins to flow out alow water to stop then add more air. Do not over pump the tank or you may ruin the bladder. Keep doing this until you are sure all of the water is out of the tank. Now to obtain the propper air pressure this can only be checked with the tank empty. Most well tanks use 27 PSI empty. Now it would be a good time to disinfect the tank with some bleach. Use an empty filter sump housing to introduce about a 1/2 cup of bleach into the tank you will need some valves to do this. Now rinse the tank by filling it and draining it sevrall times.