Best approach for a Delta handle with a spinning screw?

I dealt with a Delta Monitor 14 series last summer that did the exact same thing. That screw spinning sounds like the brass threads in the cartridge stem are stripped or the plastic sleeve is shot. If the screw won't come out, a handle puller ussually won't help much becuase the tool needs to push against the stem itself. If you try to pull it while that screw is still partially threaded, you'll just end up bending the puller's arms or snapping the metal handle. Instead of the Sawzall, I'd try a 1/8 inch cobalt drill bit. Just take it slow and aim for the center of that screw head. Most of those Delta screws are just soft brass. Once you drill the head off, the handle usually slides right off the stem with a little wiggling and a flathead for leverage. You're going to replace the cartridge anyway, so as long as you don't drill an inch deep, you won't touch the actual valve body behind the wall.

Also, soaking the whole thing in white vinegar for an hour helps more than you’d think. I usually soak a rag, wrap it tight around the base of the handle, and zip-tie it there. It softens up the calcium enough that you might get a bit more movement while you're working that screw.

I've had better luck using a heat gun or even a high-heat hair dryer before reaching for the heavy tools. Those mineral deposits act like concrete, and the spinning screw often means the plastic housing around the brass insert has softened or cracked from age. If you can get the metal handle hot enugh to expand slightly, you can usally wedge a thin flathead screwdriver behind the screw head. Apply firm outward pressure while you turn it; that typically gives the remaining threads enough bite to back out. I acutally disagree about the handle puller being a waste here. Even with the screw stuck, a Superior Tool handle puller can exert enough steady force to pull the screw right trough those stripped threads or snap the compromised plastic stem. It sounds aggressive, but it’s much safer for your tile and fiberglass than taking a Sawzall to it. I once spent an entire afternoon trying to drill one out and ended up scoring the valve body anyway. Now I just soak the assembly in a rag saturated with CLR for an hour, use the puller, and the handle usually pops. It's better to break the $40 cartridge than to risk the plumbing behind the wall.

Wow, I am just getting into fixing stuff around the house and this sounds like such an intense project! I have been lurking here to learn before my own bathroom reno starts next month. If you end up drilling it out, do you need a specific type of lubricant for the bit so it does not overheat? Also, while you are messing with the shower anyway, has anyone tried those high-pressure rainfall heads from the discount stores? I am worried they will just blow my old pipes apart if the pressure is too high, but they look so cool!

I had this exact nightmare on a guest bath reno last year. If that screw is just spinning, I found that putting heavy outward tension on the handle with a pry bar while turning the screwdriver sometimes gets the threads to catch just enugh to back out. If that fails, skip the Sawzall—I used a Dremel with a small cutoff wheel to slice a notch right trough the screw head until it literally fell apart. It’s way more precise than a drill bit if you're worried about your aim. Once the head is gone, the handle popped right off with a stiff putty knife. Saved me from a major headache.

Honestly, don't even bother with a puller yet. If the screw's spinning, the puller's just gonna put pressure on the wrong spots. I'd try grabbing the screw head with some Vise-Grips and pulling back hard while you turn it. Sometimes that extra tension's enought to make the stripped threads bite. If that's a bust, I ussually just cut the handle's collar with a Dremel. Since you're likely tossing the handle and the cartridge anyway, it's the fastest path. Just be careful not to nick the actual valve body or you're lookin' at a way bigger job. It's messy, but it beats spending three hours fighting a five-dollar screw.

Quick update—I tried that pry bar trick to get some tension on the screw, but it’s still just jumping threads. Since the puller won't work with the screw still in there, I’m thinking the Dremel suggestion is my best bet. Does anyone know if I can cut the handle off without nicking the valve body itself? I realy want to avoid opening the wall.