If the water is warm, but not hot, it may be that the temperature limit stop needs to be adjusted to allow the handle to move farther over to the left.
I've noticed that they are set from the factory pretty low.
I recently turned on my secondary shower to find that the hot water side of the divertor no longer produced hot water. I removed the trim plate and could see nothing out of the ordinary. Any suggestions on a fix? the unit is basically new as it is only used when company is in town. I took the internal apart and found nothing ?? nothing appears to be stuck, the spool was moving freely, there was 2 ports I presume hot and cold. However I can only get cold out of the volumne control valves, the adjustment screw on the hot turns in and out but no water will come out until the cold adjustment volumne control is turned out. Even when I take out the stops on the spindle shaft and free spool the valve 360 degrees I still get no hot. It will shut off in 2 spots as I turn the spindle but no where on the rotation will it give me hot. The vanity beside the tub gets hot though???
Unfortunately I have company for Christmas and no hot water -- please I need help.