My shower is dripping and the volume control cartridge needs to be replaced. A plumber looked at it but said he couldn't fix it because the large nut requires a special tool which is difficult to obtain. The photo below shows the nut which is circular with two flat sides (highlighted in red because they were difficult to see in the photo). The flat sides are about 1-3/4 inches apart but there is no way to get a wrench in there. The cartridge itself has a 17mm nut but the plumber said that by itself will not remove the cartridge.
I have not been able to find anything close to a tool that would remove the large two-sided nut so I'm wondering if the plumber is correct about the removal of this cartridge.
I have not been able to find anything close to a tool that would remove the large two-sided nut so I'm wondering if the plumber is correct about the removal of this cartridge.