Delta Shower Cartridge: Removing a Stuck One and Reinstalling

A constant drip is the sign

A constant drip from a shower head or tub spout is, according to the Delta cartridge replacement walkthrough from Home Repair Hub, a good indication that the cartridge needs changing. The job starts with the water: shut it off first, because pulling the cartridge with the water on puts water all over the place. Then open a faucet and the shower to relieve any pressure still in the system.

Taking it apart

The first step is loosening the set screw with an Allen wrench. With calcium buildup, spray CLR or vinegar on it, work some in with a Q-tip, and give it 5 or 10 minutes. The screw can come all the way out for cleaning, but it can also just be backed out a little. If removed, it should be kept somewhere safe.

Next the handle comes off. If the cartridge has not been replaced in a long time, calcium inside the handle can make it hard to remove. The same remedy applies: spray CLR or vinegar, wait 5 or 10 minutes, and repeat as necessary. After the handle, the trim sleeve comes off, and then the nut holding the cartridge in place is loosened. If the nut is stubborn, WD-40 and CLR can help clean up the calcium. In this case it was easier than expected and came off hand tight.

Removing a stuck cartridge

Many videos say the cartridge just wiggles out, but if it has been in for years it probably will not. The presenter broke the cartridge getting it out, which did not matter because it was being replaced anyway. The trick he learned afterward: put the handle back on, put the set screw back in, then pull the cartridge up and wiggle it out.

Flush and reinstall

Once the cartridge is out, Delta recommends flushing the system, so the water is turned on for 60 to 90 seconds.

Before installing the new cartridge, two things matter. The cartridge has an H marking the hot side, which goes on the left, matching the H and C on the plate. It also has a temperature regulator, meant to keep kids from scalding themselves. It is initially set at a line. To allow hotter water, pull the regulator out, turn it to the left and release it.

The cartridge goes in with the H lined up on the left and takes a little work to push in. The lock nut goes back on, and hand tight is fine. The piece of the trim kit slides back on, the handle goes on in the off position, and the set screw is tightened. Then the water is turned back on.