I used to be a distributor for NSA. I was "sold" on the NSA, now WM Filter whole house water filter.
The first unit had high pressure lines that busted while I was out of the country and flooded my finished basement, office, etc. NSA was the primary contact at this point. They paid for some of the expenses but I will never replace a lot of the things I lost in that disaster. This faulty unit cost me in dollars, sentimental items, and time away from work.
The third unit, as soon as installed, proceeded to flood my ENTIRE house with carbon and CLOGGED each and every pluming fixture in the house. Let me say that again, flooded/clogged every faucet in every bathroom and the kitchen and bar, every toilet, the refridgerator supply line, etc. It took my licensed plumber DAYS and DAYS to flush everything out of my house as well as REPLACE almost every faucet, toilet guts, supply line, etc. in my house. I had POUNDS of CARBON at the end of the makeshift drain each time the plumber would flush the system! The water filter side of the business had been assigned to NSA's "sister" company, WM Filter/Water Marque, by this time.
So here goes. The insurance company took the unit and proved it was faulty. WM Filter and NSA (both CEOs were sent certified letters) never gave me a refund, never made good on their warranty, never returned my phone calls, and never assisted me in how to get my house working again (and I do mean my ENTIRE house as it pertained to water).
They did however send me a hostile letter from an attorney informing me of my legal timeframe to sue them and recently sent me a bankruptcy notice as I am a "potential" creditor.
This disaster easily cost me over $3,000 above what the insurance company paid out. It is a sick feeling when your licensed plumber looks at you and says "we may have to re-plumb your entire house". I also lost days and days of work trying to get my house working again.
NSA likes to tout themselves as a company with a heart. What a complete and absolute joke. They won't back their products, won't service their products, won't pay the costs when it's their fault, and then turn nasty when they make a mistake. Remember, I was even one of their distributors and they treated me this way.
NEVER BUY FROM NSA, WMFILTER, or WATER MARQUE. Your home is a huge investment, don't let them ruin it!