View Full Version : Please Help - Moen 3330 Valve not working

03-23-2007, 08:46 PM
Hello all, I am hoping some of you experts can help a lost beginner like me. I just installed my Moen 3330 shower valve and figured I would pressure test the solder joints before I contined with the outlets. I removed the cartridges before soldering like the instructions say (#1 in my picture). I waited until the valve cooled down and then re-installed the cartridge and turned the water on. Then I slowly pulled on the cartridge to allow water to flow to the diverter. However, hardly any water came out. I then pulled the cartridge out again and turned the water on, again hardly any water. The instructions don't say to mess with the stop/check valve (#2 in my picture) but I tried adjusting that screw anyways. All the way in and it stops the flow completely, all the way out and still just a little flow. I then removed that stop/check valve and when I turned on the water there was lots of it coming through that now vacant hole. At least that eliminated the possibility that I had filled my fittings with solder. However, I have no idea why this stop/check valve appears to be stopping all of the flow even when backed all the way out? Of course, I didn't do the work until Friday evening and when I call the Moen helpline they are closed until Monday. Does anybody out there have any idea what is going on?

Thank you,

03-24-2007, 01:24 AM
Did you pull out both cartridges? If memory serves me right they are 2 different styles. The 1225B goes in the bottom one. When you were trying to get water, where was it coming from? The upper cartridge is the diverter. Try turning that 1 way or the other. The 2 "Screw" type items are indeed shut offs for the valve so you can isolate it from the rest of the plumbing supply and the wife/girlfriend can still do dishes or laundry!!! Make sure they are both turned out(Counter-clockwise) when testing. The larger diameter item is the pressure balancing spool. Did you remove that before soldering? Good luck. BTW, Moen will probably be open by the time you finished the loops for body sprays if you are going that route with the transfer valve. Lots of fittings & small pieces of copper. Good Luck - You'll enjoy the end results.

03-24-2007, 09:57 AM
Hello all, thank you for the replies. I did pull out both cartridges but the instructions did not say anything about pulling out the pressure balancing spool, can that get wrecked from the heat? I was very surprised when I pulled out the stop valves and found a rubber seat in there. If there was rubber in there why did the instructions not tell me to pull those out as well? Anyways, it looked like it was in good shape (but man I had to put a lot of heat to that valve!)

I did keep track of which cartridge goes where but that is not the problem because I can't even get water flow with the cartridges out. With the cartridges out I turned on the cold water supply (far right pipe) and backed the stop/check valve all the way out. Water just trickles out of the main part of the valve but I would expect full flow. When I remove the stop/check valve and turn on the water I do get full flow to the point where the stop/check valve was so the problem appears to be either the stop/check valve itself or the port between the stop/check valve and the main valve body. Honestly, I look in there and cannot see how the water gets from the inlet port to the main body, there doesn't seem to be anywhere for the water to go. I wish I had a diagram of what that valve body casting looks like.

03-24-2007, 01:44 PM
Do you have pressure turned on to both the hot and cold sides? If not, ther pressure spool will shut off all flow out of the faucet.


03-24-2007, 05:06 PM
You didn't leave yourself much room to connect the outlets of the transfer valve!

Once you get this problem resolved, I would confirm that the stop checks are working OK and replace them if necessary.

First step is to remove the balancing spool and the cartridges and flush. Then reinstall the spool and both cartridges.

03-24-2007, 08:08 PM
Thank you hj, that was it!

I finished the rest of plumbing today. It looks pretty bad but it was my first time soldering ever. The pressure is great when I only have one head going, unfortunately it drops significantly when I open up all four :(

Now I just hope that my 2" drain will be able to handle the water from 5 shower heads :)

Thanks for all your help.

03-24-2007, 08:10 PM
Thanks Jimbo, I didn't see your post but that is exactly what I did. First I flushed with the balancing spool out then put it back in and flushed again. Then installed the bottom cartridge and flushed again, then finally installed the top cartridge and flushed each head.


03-25-2007, 07:16 AM
Fortunately, the 1/2 " supply will limit the total water flow to an amount which your 2" drain will easily handle.

03-25-2007, 01:52 PM
How many gpm is that valve rated for? Compare that to the specs for the body sprays. Also, is your water pressure coming into the house in the range suggested for the valve? The valves and shower heads are speced at certain pressures. If you don't have that pressure, the flow will be less. The steel strapping probably won't cause problems, but copper might have been better choice.

03-25-2007, 06:58 PM
The valve, shower head and body sprays all came as one package but there is absolutely no information on the valve. Each body spray and the shower head is 2.5 gpm so I am guessing the valve would be rated for 12.5 gpm? I cannot find any recommended pressure specs for the valve but I did test my pressure prior to installation and I get about 78 psi. I did phone Moen and asked them if this would be sufficient for this valve/body spray combo and they said 78 psi was plenty, anything over 65 would work just fine. I believed them, purchased and installed the unit, and know I am wondering what their definition of "fine" is. I suppose I was probably not being realistic expecting to get "shower head" type water pressure out of 5 nozzles when I used to get that out of 1.

I had heard that you shouldn't use two dissimilar metals together in a plumbing system but I had just assumed that was for the wetted parts, I didn't realize it could cause a problem just using steel for strapping.

thank you,

03-25-2007, 07:57 PM
water would be flowing at 15 feet per second in your 1/2" diameter pipe, to feed 12.5 GpM.

put plastic between the steel and the copper.


edit: you may find performance is unacceptable, but this will depend on so many factors that it may not be worth discussing in advacne