I have an old Grohe thermostatic shower valve. The water temperature only goes up to lukewarm, about 100 degrees. Previously it worked great for many years.
I don’t know the exact model. Based on the temperature ring and the shape of the front of the cartridge, the closest I can see in parts diagrams is 34419, but I don’t know for sure. Note that the check valves (and shutoffs?) are mounted in a line in the rough in. Also, unlike other models, there is no green plastic temp adjustment, and the cartridge appears to be held in place with an E clip in front of the hex nut. I believe it is ¾ inch, because all the piping to the shower is ¾.
Turning clockwise, the temperature adjusts down as it should. Turning counter-clockwise, the water gets hotter, but the upper limit is not high enough. Note that there is no button to allow going past the high set point limit on the outer (visible) ring: this is only visible when the knob and sleeve are removed. However, when turning, it can be pushed past the original set point of 100, but the temperature at that point is only about 90 degrees.
Question 1: How do I adjust the temperature setting? The black ring that the stop fits into is hard pressed against the hex nut. I didn’t want to pry it out (in case it breaks) to try to rotate it so that the stop semi-circular hole will allow more turn counter-clockwise. Is there another way to adjust the high limit?
Question 2: Could this be a cartridge failure, or another part failure? Can the cartridge/model be identified from these photos, or do I need to remove it?
I don’t know the exact model. Based on the temperature ring and the shape of the front of the cartridge, the closest I can see in parts diagrams is 34419, but I don’t know for sure. Note that the check valves (and shutoffs?) are mounted in a line in the rough in. Also, unlike other models, there is no green plastic temp adjustment, and the cartridge appears to be held in place with an E clip in front of the hex nut. I believe it is ¾ inch, because all the piping to the shower is ¾.
Turning clockwise, the temperature adjusts down as it should. Turning counter-clockwise, the water gets hotter, but the upper limit is not high enough. Note that there is no button to allow going past the high set point limit on the outer (visible) ring: this is only visible when the knob and sleeve are removed. However, when turning, it can be pushed past the original set point of 100, but the temperature at that point is only about 90 degrees.
Question 1: How do I adjust the temperature setting? The black ring that the stop fits into is hard pressed against the hex nut. I didn’t want to pry it out (in case it breaks) to try to rotate it so that the stop semi-circular hole will allow more turn counter-clockwise. Is there another way to adjust the high limit?
Question 2: Could this be a cartridge failure, or another part failure? Can the cartridge/model be identified from these photos, or do I need to remove it?
