Moen positemp problem - clogged??

Water flow in my shower was slowing down and it was also beginning to drip. Figured it was time to replace the Moen posi-temp cartridge. From past experience, I knew that these were difficult to remove and so I had a plumber come out.

He used the Moen puller and broke the inner metal part of the cartridge but was able to remove the rest of the plastic cartridge in bits in pieces. It all finally came out! Flushed out the posi-temp valve to clear out any debris and there was good water flow. Installed a brand new cartridge, turned on the water but no water! Tried two new different cartridges, still no water!

He blew into the shower head arm and was unable to get any air through. He concluded that there was some obstruction in the posi-temp valve. He tried blowing 100 psi of compressed air in through the shower head arm but it did not clear the blockage.

Question:
Has anyone seen this type of blockage problem before and is there any way to clear it out? Is my only option to replace the entire valve?

Thanks, any advice is appreciated.

lost bit of rubber

likely part of the black rubber rectangular gasket sheared off and is lodged in shower port of valve, you will need a strong o ring pick and maybe a new cartridge to fix, you first need to turn water off to faucet, disassemble faucet, with cartridge removed there will be a port at 12 o clock inside of where the cartridge goes, poke and pry up in the port with a good quality o ring pick to dislodge rubber bits, reassemble faucet and all should be good as long as pressure was good before starting, if not there may be a mineral deposit build up in this area, moen faucets are really nice in that there are few moving parts to go wrong



Moen replacement 1222 for the Posi-Temp Shower Valve

I have the same problem no cold water and only alittle hot water comes out. I changed the cartridge and still same problem

Mikeerok said:

I have the same problem no cold water and only alittle hot water comes out. I changed the cartridge and still same problem

Click to expand...

With the cartridge removed, turn on the water to blow all the crud out of the valve body. If there are stops on the valve, exercise them to help clear any debris. Make sure the stops are all the way open. Lube the inside of the valve body with a light coat of silicone grease before you reassemble. Dont use aftermarket cartridges, buy only the original Moen-branded cartridge.