I had a leaky Moen faucet (Moen 4600) so I removed the old cartridge and replaced it with a new brass replacement cartridge (model 1200.) Since replacing the cartridge I now have a leak from the valve stem, that leaks faster the more I open the valve. It appears to be coming from the outside collar of the cartridge. Here is a video of the leak so you can see exactly what I am talking about:

Video of the leaky faucet

Is this caused by a poor fitting cartridge / o-ring or is it possibly due to wear on the faucet itself? What can I do to stop this leak?

  • You mention Moen 1220, but I don't believe there is a 1220 - just a 1200. Is that correct?
    – user27714
    Nov 7, 2014 at 17:53

7 Answers 7


I contacted Moen directly with this same question and they let me know that they recommended a model 1225 replacement cartridge instead (that's what I get for trusting the guy at the hardware store to look up the matching part for me). Technically either one will work but apparently the plastic 1225 offers a tighter fit than the brass (and more expensive) 1220.

Moen also recommended cleaning out the inside of the valve with an old toothbrush or bottle brush and then flushing thoroughly before installing the new cartridge.

I will update this once I know if the new cartridge resolves my leak.

Update: After the installation of the model 1225 cartridge, the faucet works without any leaks from the stem. With the addition of a new knob the whole fixture is working better than new.

The moral of the story here is, when in doubt, try to contact the vendor (and post your results!)


The same thing happened to me when I tried to replace the original Moen brass cartridge with a new brass cartridge (1220). I went to Lowe's and bought the plastic cartridge (1225) and put it in. No leaks, and the valve works with a finger tip touch. No more pulling on the knob to get the water started. In addition, with the original valve removed, I cleaned the inside of the housing with Lime-Away and a toothbrush so that it would be extra clean.

Who would have thought the plastic valve would be better than the brass?

  • Ditto; I had the same problem (and it seems to be widespread with Moen replacement cartridges). I removed the cartridge for the umpteenth time (I was getting good at it). I then scrubbed the inside of the pipe thoroughly with lime-away and an old toothbrush. I had wifey hold a bucket over the pipe while I turned the hot water on for three seconds, then the cold. No leaks! I'm a believer.
    – user23391
    Jun 29, 2014 at 14:36

I had the same problem. The new one I found had a point in the top o-ring because there was a plastic defect where the seams came together like extra plastic or blade. I scraped that off and then the o-ring was flat all the way around. No leaks.

  • The name for what you ran into is "excessive mold flash", but yes -- that could cause the O-ring to not seal quite right... Apr 5, 2015 at 17:27

Whenever we have had any problem with any Moen faucet that we purchased we just returned the faucet to Moen and they sent us a new one. The inside of our kitchen faucet rusted out and they sent us a brand new one even after we had used the old one for 10 years! You must be the original owner and have proof of original purchase (I keep all our home improvement receipts for things like that). Moen stands behind their products. Based on our family's positive experience and having grown up a plumber's daughter, I wouldn't buy anything else.


The housing has some particles in it; take out the housing and clean the inlets.


I had this same issue. A new Moen faucet in my bathroom and after a few months it started leaking from the tap. Rather than run out and get a new cartridge I attempted to see what may be causing the problem so I pulled off the cold water handle (which was leaking, hot water handle seemed fine) and using my hand I slowly turned the top of the cartridge and found that with a very slight adjustment the water stopped so I put the handle back on gently and screwed it back down while holding the handle to prevent it from moving. I'm telling everybody in the house to be gentle when turning the water on and off but my leak is fixed without replacing any parts.

I'm on a well so leaks are bad and I hope this helps some people.

Just a quick update on my tap situation. The leak was back again today and I thought for sure I was going to have to replace the cartridge but I'm trying to avoid it as the taps are only 2 months old.

I took the handle off and turned the tap 180 degrees and the leak stopped. My gut feeling is that there is something keeping it from sitting completely down but the handles were not touched as they were pre-assembled when purchased, I just sat the new faucet where the old one was after I used a razor blade to make sure the entire sink was clear of obstruction and then cleaned it. It's okay again but I'm sure I'll have to replace the cartridge but as I stated, the taps are only 2 months old and for what I paid it's hard to figure the cartridge is bad.

I also checked for hairline cracks and didn't see any in the brass. I do agree that plastic might be the better option so long as you're cautious as to how tight you go.

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    – Niall C.
    May 25, 2015 at 13:31

OK for me this happened when replacing a cartridge on a moen kitchen sink faucet -- gushing water!

Turns out that the instructions list the "alignment angle" as having one large hole at the top, and the two smaller holes at the bottom. But on my faucet it was the large hole at about 5 o'clock so I inserted it to match and voila, no leaks. That was scary though, it was leaking more with the replacement than with the original :)

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