Hello all, not sure whats going on but installed a new Moentrol valve (3320?) and water pressure is about 1/2 it should be. Took out top cartridge and messed around with volume limiters which I had all the way out, turned them in a few turns and wham! more pressure, go figure. Now that was done with the top cartridge out and when I put the cartridge back in the pressure is low again. So am I crazy can there be blockages to both tub and shower?? or is there a cartridge mismatch? Baby on the way and need to get this buttoned up asap! Any suggestions or other ? Any help is appreciated.