Minor air in line for decades

[Copymutt]

Curious what may be the cause behind this. The shower in my garage spits a small amount of air just as the well pump approaches its 60# shut off. Been like this forever. There is a monitor pressure gauge just outside the shower and all is normal. My thought is a bit of cavitation from the pump impeller might be behind this. Anyone have another thought?

 

[Jeff Handy]

Change the shower cartridge.
The o rings or seals inside might be getting weak, and at 60 psi they start to leak.

 

[Copymutt]

Thanks, I will pull the cover and inspect for external water. This was probably the cheapest unit I could find back in 96.

 

[Jeff Handy]

By leaking, I mean they are possibly letting water go up to the shower head, even though the shower valve is off.

 

[Copymutt]

No drips from the head. Understand there is no diverted here, just straight shower so only infiltration of air would leave a telltale wet area. I’m gonna try to duplicate w/ the shower head off. Might give some clues.

 

[Ferdinand]

Unrelated to leaking seals or pump pressure, but I had a similar mystery with air building up every day in my water line with no obvious water leaking out anywhere. With positive pressure in the line, how the heck is air getting into the line without water leaking out? It turned out to be caused by the magnesium anode in our newly installed water heater reacting with the salt from our water softener system. Changing to an aluminum anode solved that completely. See write-up in this post. Air in hot water heater.

 

[Copymutt]

Thank you Ferdinand. I’ve decided to replace the cartridge as it’s very tough to control temp. anyway. This shower is supplied by a 6gal. electric, so if the problem is still there I’ll ck. the operation w/ just cold water. Thx. for the tip.
Jim