I have a friedrich grohe shower (Jado) it's a control temperature bar from 60 to 120 degres. My problem is I have a very low water flow coming from the hot water. For the cold water there is no problem,everything is OK. I have check my debit from the beginning of the main cartridge (hot water) everything is OK. What do you think is my problem?

Gabriel.

I assume this hot water volume problem is only in this faucet, correct ?

These faucets have temperature balancing mechanism inside. Chances are this mechanism is not working properly. You need to remove cartridge and most likely buy new one. That will solve the problem.

Let us know how you did... Milo