Moen Posi-Temp, Low Flow at tub spout

[Jsmallberries]

20 year old, single handle Moen, turn not pull, shower tub combo.

Hot or cold or combined, low flow from tub spout, and the pressure lessens even more within 30 seconds or so after running the water.

The main flow throughout the house is somewhat low, but this is worse here and most likely a separate issue.

Would a clogged or defective shower stem cause this? Or what should I look for?

 

[Terry]

Has it always been low or is this recent?

If recent perhaps the cartridge. Moen Posi-Temp

 

[Sponsor]

 

[Jsmallberries]

Per distressed neighbor, recent problem. The whole house has fairly weak pressure, but this location is really bad.

 

[Reach4]

Get a water pressure gauge with a garden hose thread (GH /GHT). They are pretty cheap and available.

Connect it to the WH drain valve, and turn on the drain. Run hot water and see what the pressure does. If the pressure drops a lot, the pressure drop is on the way to the WH. You would first check that the valve for the water heater water was fully open. Then you might suspect the heat trap on the way in.

If the WH pressure stays up pretty well as you run hot at the shower, then the blockage is on the way out. There is a heat trap there too.

Also try your gauge on a cold tap to make sure the problem is for hot only. Outside faucet, or a laundry tap is good.

You can watch the hot pressure at the laundry while somebody runs the shower. If that stays up, then the restriction is after the hot water splits off between the bathroom and the laundry area.

 

[Jsmallberries]

Thanks R4, a work in progress.

What about this tool for Posi Temp 1222 Moen

General Tools 1809 Stem and Cartridge Puller

 

[Jsmallberries]

So I replaced the Moen valve stem, now has very good pressure and the shower handle turns effortlessly.

Was a bitch to get out, 19 years, but they have a softener installed, really hard water here, my own replacement, pulled the guts out leaving the casing fused in the valve body, that was an experience....

My question, the plastic piece that comes with the replacement doesn't work, as the tabs from the old cartridge are recessed into the shower valve body. I had to cut them off so it would turn. I did that and used a danco puller, went back and forth between the two, finally got it to turn.

Not sure I would do that again for someone, as the risk of failure is pretty high with these