7000SXT - noise problem

[sw1911sc]

I have had a 7000SXT for a year and about two months ago it start making a loud noise with every a toilet, washer load, or a shower is running. The 7000 is in the garage and is so loud it is hard to ignore upstairs with all doors closed. THe noise is a kind of loud fluttering, like the pump is running dry or something. Water flow is not obstructed and the unit seems to function properly other than the noise. Please help me understand the possible sources for such noise.

[ion_avenger]

Sounds like maybe a seal issue. If stuff gets stuck between the seals and the piston or body it can make a howling\shuddering noise. Try cycling in manually and see if it gets quieter. Do you have a service manual for it?