BlakeLinda wrote:
Thank you John. I agree that I thought it sounded like air was in the line. I ran the hot water at both sinks and shower. The only way I know to fill the hot water tank is to open the hot water outlets at the sinks & shower. Is there more I should do ?
Thank you
Air is pesky stuff. I used to blow out all my lines, but the past few years I've taken to using anti-freeze instead. That makes it so you don't have to push much air out. If you have captured air somewhere, the pump can pressurize the air causing the hammering sound.
When I de-winterize, I generally do it from city water and a pressurized hose... and I start with opening the bypass valves on the water heater, and opening the pop-off valve on the water heater and the kitchen HW faucet. Then turn on your hose. Close the pressure release valve on the WH when water starts flowing out, and then close the kitchen HW faucet it when water runs clear and air stops coming out of the line. That fills the HW tank, and gets the air (and/or antifreeze) out of the hot water line the furtherest from the city water connection. Then I start with each of the successive furthest and highest lines, kitchen cold, bath hot then cold, toilet and then shower hot and cold, including the exterior shower. Then, after all of the air/anti-freeze is run out, I go back to the kitchen and run both the hot and cold again until I'm reasonably sure there is no more air in the lines anywhere. After I've got the lines clear of air/anti-freeze from the pressurized city water, THEN I disconnect the hose from the city water spigot and fill the tank... after that, the water pump should self-prime and pressurize against the water already in the system with a minimum of air in the lines. I usually run the cold at the kitchen for a minute or two more using the pump which gets any of the air out that may have been pumped in during priming.
Let us know what you figure out.
Roger