Water leak identified by my Moen Flow Protection Device

Kaia

I have a Flow By Moen auto shout off valve installed on my condo water intake line. I have been receiving critical alerts for months that continuously turn off the valve and leaving us with no water until I turn the device back on. Then in a few minute it happens again. I have had a Plumber out twice and he found nothing. I have had the walls, ceilings, and the attic scanned with an infrared camera and found nothing. The hot water circulating pump is turned off and the valve is closed. I have tried to reset the device and still no change. When i turn off the hot water to the condo and all alerts stop. After identifying that the problem occurs only when the hot water is turned on I have tried: Installing a new expansion tank (setting it’s air pressure to match the incoming water pressure). Checking for expanded water coming from the expansion overflow pipe. There was none. I have called Moen many times and after working with them the last timeI was told I need to hire a professional plumber which as stated previously I already did. I am at a loss. Has anyone else had a similar problem and if so how did you fix it? 

Intplm.

Yes. I have had check valves that malfunction, causing a misread. They can make the water bounce in the piping, making the thing read a leak, but there isn't one. Others have also caused similar issues. They can be a real pain. I have been wanting to install one for myself, but can't seem to find one that won't misread.

mattmia2

need a check valve before the expansion tank so the pressure changes in the main can't cause water to flow in and out of the expansion tank.

PeteA

do other water services feed from the same room and do they have MOENs on them? Is it possible for a duplicate device ID to be on another MOEN shut off valve in the area? I guess this can be tested just by seeing if it ever reads flow at a time when you are sure nothing else is running. Just throwing it out there since this tech stuff can be a real head scratcher with the wifi or bluetooth stuff.

Kaos

Did you try turning off the water feed to your toilets? Does it still trip? Sometimes a leaky fill valve looks like a water leak.

Jamie Hall

https://forum.heatinghelp.com/discussion/comment/1853306#Comment_1853306

Um… err… seems to me that that will rather defeat the purpose of the expansion tank? If the check won't let water in, there's no point to the tank at all. If it's set to not let water back out, the tank should eventually charge to the peak pressure in the system and then just sit there.

What am I missing?

I've never rally been convinced by leak detectors. Foor a simple reason: define "leak". If you define it as a small, but continuous, flow, then as @Kaos notes a slightly off toilet tank fill is a frequent villain — but it could be a dripping faucet somewhere. Or it could be a classic leak from a pipe joint or pinhole — and how is the detector to determine the difference? Got to admit that if I had one, I'd be fooling with it to see under what flow conditions it tripped… just to be a pest!

mattmia2

https://forum.heatinghelp.com/discussion/comment/1853314#Comment_1853314

in the cold water feed to the water heater before the expansion tank and heater tank so if the pressure in the main drops the water from the expansion tank can't flow out to the main. the whole hot water system with the tank is beyond the check valve. I suppose if the pressure rises fast enough that could still trigger it. in that case you'd need a pressure reducing valve too.