I've recently moved into an older house and have been troubleshooting the shower faucets for about six months now. No matter how many times we replace the handles and cartridges, it seems like each time we use the shower, the cartridge and the clear plastic handle start to feel soft. Just to clarify, the hot water isn't scalding—it's at a temperature where I can still comfortably do the dishes. The real issue is that when the handle and cartridge heat up, they get too loose, making it difficult for me to turn the water off. If I shut off the main hot water valve and let everything cool down, it works fine again. Is this something that should be happening? I'm planning on replacing the pipes and faucets with new ones, but that's at least a year away, so I'm trying to figure out what's going on. Any insight would be appreciated!
3 Answers
I've honestly never heard of that happening before. It's definitely a strange situation, and it might be worth investigating further. Maybe check your water heater settings just to be sure everything is normal there, as even a mix of hot and cold could make it feel less hot to you while still being dangerously hot where it matters.
It sounds like the shower trim might be the culprit here. If you're using a Moen or Delta model, you are usually able to replace just the trim for around $100. This could potentially resolve the issue without completely overhauling everything just yet. What kind of trim do you have?
That is definitely odd! Especially since you're saying the water isn’t scalding. Could it be that the handle is actually melting or deforming? If you can, maybe post some pictures of it. That could really help in figuring out what's going wrong!

We never were quite sure. We found a set at Ace Hardware that was Delta, and that worked for a few months, but the Delta plastic handles broke inside. We’re on our second set of both cartridges and handles in about eight months.