Corrosion in Shower valve

[cgarai]

I have just replaced the valve below in a Kohler thermostatic mixer. The corrosion built up on the disk and caused the unit to start to drip. Is this a common problem? Should I be concerned? Could I have just cleaned it off an reinstalled it or is it finished?

The house is on well water (13GPG hardness) and has a water softener using potassium chloride instead of sodium. The plumbing is all PEX except where copper connects to shower valves. The house has only been occupied for 2.5 years.
Thanks,
Chris

 

[ditttohead]

Not common. The valve looks good except for the corrosion spot. Probably some impurity issue with the manufacturing, but really hard to say for sure. Rebuild the valve, and post your well water test that should have been done when you became the occupant. Better yet, get an updated water test done. Remember, if you are on a private well, you are the "municipality".

 

[Sponsor]

 

[cgarai]

Attached are the two water tests. The older was taken on the day the well was drilled, taken at the well head. The newer was a few year before occupancy and was taken at the 10K gal holding tank.

What should I have the water tested for? Should I test both before and after the water softener?

Thanks.

 

[ditttohead]

Your water is quite nice for the basics. The corrosion on the valve might simply be a defect in the material of the valve. My only concern with your water is the LSI or potential for corrosive water. pH is only an indicator, water can still be very corrosive when it is above 7.0 For now, I would carefully inspect the brass body of the shower valve when you replace the cartridge. Carefull check the wetted surfaces to make sure you don't see any pitting of the brass body.

Why are you using KCL?

 

[cgarai]

It's been a year and now the shower output seemed low, so I took the heads apart and found out that the screens were clogged with a mix of what looked like pipe dope "dust" and green corrosion flecks. The picture shows more corrosion than pipe dope on this particular head.

The house is plumbed with PEX; copper and brass mostly at the terminals. I measured the pH at about 7.6-7.8 and the Total Alkalinity at 160-170. Something is causing some corrosion. What should I have the water tested for?

I'm using KCl as my understanding is that the effluent is easier on the soil and potassium is easier on the drinkers as well. That said, we typically treat the non-softened water.


Thanks,

Chris

 

[ditttohead]

Do you have a recirculating pump on the water heater? Are the pex connections brass?

 

[Reach4]

Any chance there is algae? Maybe not the brightest green, but what about the darker green? Is the tank tan and in the sun?

 

[ditttohead]

I am a bit color blind so I didn't notice how green that was until I used a color app... nasty green. Is it soft? Mushy? PEX has a tendency to grow algae inside of itself. One of the reasons I am not a huge fan of PEX. Please... nobody start a PEX vs copper war, too old of a fight to bother with. FYI, I used both when I was working the field daily.

 

[cgarai]

Yes there is a recirc pump. It is a push button demand recirc, so it's not on very often. What would that do?

The PEX connections are a mix of the composite and the brass styles. The hot water heater is 120g Heat Transfer Products Phoenix, which has a stainless steel tank.

The green is not algae. It is hard even wet and now while dry. Fairly certain that it is corrosion.

Thanks

 

[cgarai]

Do I need to worry about this? If I do, what should I test for?
Thanks,

Chris

 

[ditttohead]

Many brass pex fittings are porrly made (cheap) and simply fall apart especially at higher flow rates. The recirc pumps tend to be very oversized and cause excessive damage to the 90 degree fittings. I would recommend removing a couple of random brass pex fittings and replace them. Inspect them and see if there is any obvious damage.

 

[cgarai]

Removing random brass fittings is my worst nightmare. It's all behind finished walls. Also there are very few right angle fittings if any as I don't like to use them for the reason that they reduce flow. The recirc system has none. Pex is flexible, take advantage of that and minimize RA fittings.

I doubt that it is the recirc pump. This is a demand pump that runs for 2 minutes when you push a button in one of the remote baths. The kitchen is close to the HWH so no recirc there. That button probably gets pushed 3 times a day on average.

 

[ditttohead]

Looks like something is falling apart in your system. Maybe the pump impeller. This is one of those things you may have to wait until something fails.