eephys
New Member
I just dealt with similar problems with my GE GXWH40L filter on a 1" line. I had continuous banging in the house, thought it was a loose pipe but couldn't find one loose. I put a pressure gauge on the outside faucet, found the pressure at a steady 60 psi - except when the noise happened , there was a pulse in the pressure to 65 psi or so every second or less, like 70-80 times a minute. This was with no flow into the house. I even have an expansion tank on the line in the house and small arrestors at the washing machine. The town water guy denied any town responsibility, but I'm sure the pressure pulsing is there from the 16" main out in the street. The noises did get worse as the filter cartridge got older. My filter is plumbed like callmebill's with three ball valves for external bypass. With the external bypass open and the other two shut, there was no noise. I eventually figured out that the build-up of sediment increased the pressure drop across the filter and made the cartridge move slightly in the housing, just enough to make it bang with every pressure pulse. It's just possible that the cartridge actually got compressed a bit and became shorter as it banged making the banging even worse. The noise was transmitted by the filter bracket to the floor joist. I installed a Watts LF U5B Z3 pressure reducing valve (not cheap!) near the water meter, set it for 45 psi static pressure. The pressure reducing valve blocks the pressure pulses. Now, all is quiet! With some water running, the pressure in the house drops to about 38 psi, reducing the flow a little more, but it does save on hot water. Silence is golden!