Phyn Smart Water Assistant review
Phyn Smart Water Assistant (PHYCF001) Under-Sink Water Monitor
By Tom Calder
A DIY under-sink monitor that sends leak and freeze alerts. It cannot turn the water off.
- Best for
- A no-plumber way to watch for leaks
- Skip it if
- You want the water shut off automatically
as of Nov 14, 2026, 5:36 PM ET · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.We earn a commission if you buy through the retailer links on this page. It doesn't change our verdict. How we make money →
Researched, not used. We haven't used this product. This review is built from the maker's specifications, owner reports and our own sizing.
What we like
- DIY under one sink, no plumber
- Freeze warnings
- No hub or subscription (maker)
Worth knowing
- Cannot shut off water
- Needs an outlet and 3/8 in angle stops under the sink
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Who shouldn't buy this
Don't buy it if you want the water shut off automatically.
Key specs
| Pipe size | 3/8 in hot and cold angle stops |
| Install | DIY under one sink |
| Detects by | Pressure sensing, freeze warnings |
| Connects by | Wi-Fi; no hub or subscription |
This is a Researched review: we haven't used this product. We check every specification against at least two independent sources, re-check the US price on a schedule where we can track it automatically, and say plainly who it isn't for. Commissions never change a rating.
If this isn’t the one
Best for Whole-home auto shutoff on a 3/4 in main
as of Nov 14, 2026, 5:36 PM ET · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
Best for Whole-home auto shutoff on a larger main
as of Nov 14, 2026, 5:36 PM ET · Details
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.Best for Whole-home shutoff with freeze warnings
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