Moen 2570 valve water flow restricted

[questdiscmask]

Hello,

Here is a whats going on:

I recently purchased Moen products for three bathrooms: two complete sets of shower valves (Moen 2570) with trims (Moen Align), plus one additional trim set (valve not yet purchased).
Issue Details:
- After installing the new Moen valve, water flow dropped and when I check it is approximately 0.5 GPM (measured at my tankless water heater), despite the shower head being rated for 1.75-1.8 GPM
- When the cartridge is removed, the flow through the valve body is excellent (approximately 3.7 GPM for hot water alone, I estimate 6+ GPM total hot + cold)
- As soon as any cartridge is installed (both original and replacement cartridges which Moen supoort sent), the flow immediately drops to 0.5 GPM
- Water pressure in the house is strong (80-100 PSI) - I need to install pressure reducing valve.
Steps Already Taken:
1. Valve installed by a certified professional plumber
2. Thoroughly flushed the system before installing the replacement cartridges
3. Tested without the shower head or handheld shower to eliminate it as a potential cause
4. Had a plumber remove and check all tubing of shower system
5. Installed the replacement cartridges Moen provided - same issue persists

I previously contacted Moen on January 31st regarding issue I am facing, and Moen supoort was helpful in sending 2 replacement cartridges, but the problem unfortunately persists. After hearing all the steps I have taken, they identified it as a cartridge issue.
Please advise on how I can proceed to resolve these issue.

Some video for understaning what is going on:

Note I am not a plumber, but homeowner, so dont judge me proffesionally

 

[GReynolds929]

Occurring at both valve locations or just one. What shower rail is that has the rail been removed and output tested at drop eared elbow?

 

[Sponsor]

 

[questdiscmask]

I didn't install 2nd valve yet, will probably install tomorrow. I removed shower rail, same thing. I suspect that nipple which connects to the rail is causing this - it has white plastic water flow restricter (as far as i understand) thats probably clogged. I found that plastic inside a nipple in the shower installation video. Will remove that nipple and remove the plastic to test it.

 

[questdiscmask]

Problem solved. It was a plastic inside barb nipple of shower system - it was clogged. We end up breaking the plastic, which i assume is water flow reducer and filter. Now the flow is perfect. See pictures in next post.

 

[questdiscmask]

See pictures