My guess is that one of the PVC pipes got some sand in it during your build. Mike Scott should be your original installer and it should have been their responsibility to flush the newly installed lines before faucet/showerhead/appliance hookups. Hopefully it's only the hot water lines. Have Mike Scott come out and clear all sediment filters and screens (don't forget your refrigerator water supply) and flush your system at the furthest points. I would think the furthest point would be the master bath but it'll depend on your model. If doing yourself, I'd take the shower head off and open hot then cold lines one at a time full blast for about 10-15 minutes.
Your only problem may be that you had the filter and softener installed so Mike Scott might try to blame the company you had install those, as it appears they already have. If so , call that company and have them do the work I mentioned above and tell them that Mike Scott blamed them. I just don't see how it would be the filter installer because all their work is above ground. The original pipe install are buried pipes that are cut and glued below grade.
JMHO on this and it might be something happening that is above my pay grade to figure out but you have to advocate for yourself and don't just take their word on things. I had a window problem where the builder blamed the manufacturer and visa-versa and when they finally opened it up after my insistence I wouldn't accept their bandaid repair, it was discovered that the install was set to low so they never secured to the header. So it WAS the installers. It took 8 MONTHS to finally get it fixed correctly (this was during COVID so this may account for some of the time) but I think they were just waiting for me to get tired of complaining and accept it the way it was.

You may want to consider adding a whole house water filter. This filter is installed inline to your water supply line entering your house and just before your water softener. Home Depot and Lowe’s sells them for roughly $100. I installed one when I moved in and changed it after the first 90 days. I was surprised how much sediment it had collected. I changed it a second time 90 days later (after 6 months of ownership) and it was much cleaner. Now I will change it every year. Good luck.

By the way, simple installation. A DIY project for most homeowners.

Would you mind telling us what village you're in

We're moving into WellPoint soon and I want to be sure to check for this
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Broken Water Softener Tank
 

We had similar symptoms and the “sand” turned out to be resin from the water softener tank. The softener company rebuilt the tank and found that the filters inside of the tank had broken letting the resin into our water supply and clogging faucets and washing machine. Very weird symptoms.

(The softener has not worked properly since then - they should have replaced the tank.)

I so agree with what you said and how you said it. Dependable, trustworthy warranty department who bend over backward to help......unless you get impossibly snarly.

The OP said that the house already has both filter and softener systems.

Correct. We had Nova install both a whole house water filtration unit as well as a NaCl softener (and RO, but that's not really relevant).

And I'm catching up to this thread since there was a lot of helpful information and questions so I'll try to reply to each here:

* RE: Warranty of the appliances. First, these are our own new appliances as new builds don't come with washing machines or dryers (just a refrigerator, oven/range, and dishwasher). So of course I wouldn't expect them to warranty them or even those they installed. But I would think they would be accountable for any damage if basic services they DO warranty to some standard (i.e. plumbing, electrical, etc.) do affect them regardless of provider (developer or buyer).

* RE: Filter at hot water heater: good question. I have no idea if there is one, but I would expect any H2O entry point to be properly screened/set just like the quality of our potable water to be at some standard. So aside from maintenance of the units themselves, home owners shouldn't have to worry about them.

* For Ham_and_Cheese, we are located in Waters Edge - so not far from Wellpoint. Not sure if it's similar as up north, but we've notice significant sandstorms when the wind blows here as most of this area - if not the entire state of Florida - seems to be built on sand.

* For eeroger: Holy $*!T! That would be a nightmare if the HVAC lines were clogged. Was your issue sand too? Or other? I've already flushed my condensation lines and ordered new filters, coil cleaner, vinegar, and an attachment for our shop vac to suck the sludge at least quarterly and new filters to keep on top of maintenance of our system. We run COLD in our house and what many don't realize is these units don't get a break like they do up north so keeping them clean and running efficiently is paramount to their longevity.

Thanks, all!

Thanks! You made me look :-)

Here's instructions for cleaning the inlet filter on the Rheem tankless we have.

Easy to do, just did mine, it was about 30% clogged after 5+ years.

Mostly debris from the annual flushing. So this filter definitely needs to be cleaned after the annual flush.

https://youtu.be/jQ7Y6ujFbWg

Super helpful - thanks!

If you haven't seen it, Rusty Nelson also has some great home maintenance videos on how to maintain our systems, including tankless hot water heaters: https://www.youtube.com/watch?v=APo7dHvQ3cU&t=760s

When I bought my house, the builder did offer to install a washer and dryer for an additional charge. But, it was not warranted by the builder. Note the builder has no one who can repair appliances. That is why they do not warrant appliances.

When people talk about the Nova and or the softener being the problem, It's theoretically possible that the softener resin may be leaking into the water supply. You may be seeing some of the resin and not sand. Especially, if you keep seeing it. There is no way sediment is passing through the Nova Filter. Either way if both are Nova, I would call them and I'm sure they will come out and investigate..

No sand since clearing the lines - I suspect it was here before Nova. Could it be the plumbing stubs (if that is indeed what they are) that one sees on new lots that are left uncapped?

We had same problem, Mike Scott never blew out the lines. Plugged up fridge, had a broken pipe behind it that had the air hammer broken off and filled it with cement. Took 9 years for the cement to break down and we had water leak. Plumber said it should have been fixed not our fault. We got stuck with repairing it

Wow - sorry to hear that. Do you mind if I ask in what village or area you're located?

I'm hoping we didn't have much sand accumulate and what we did get was flushed after the recent clogging, but who knows, and I'm not sure what can be done now, if anything.