I'm in a 9-month old house where the builder uses Moen exclusively.
I've had intermittent problems with no hot water in the master shower, and continous problems with the guest bath. If I turn the water on, there's a lot of cold water, but it dwindles to practically nothing if it's turned all the way to hot.

The plumber who installed the fixtures was already out once, pulled the cartridges to check for debris, and claimed that it was my fault because I don't run the water frequently enough in the guest bath so the cartridge froze.

When the plumber came last time, I had already managed to get hot water from the guest bath tub by letting it run. I got a lot of brown water when it finally kicked in. Now the plumber is coming back because (1) I don't have hot water in that tub again, and (2) apparently something blew when I last turned it on, because there's major water damage in the sheetrock next to the tub and in the closet behind it.

I know the master bath has Monticello; guest bath has a cheaper version (I don't know model number; paperwork is at home). Are Moen shower faucets so bad that they won't work if you don't run them daily, or am I being fed a line?