Water doesn’t stay hot only in shower

[CluelessInMA]

Feb 8th we replaced our whole house filter and replaced the arsenic filter with a point of use arsenic filter. The day before, we were instructed to flush the well with bleach since we had bacteria in the water. So we hadn’t really used the water after that until after the new filters were put in. When we were flushing the lines, the water was dirty and there was some sediment that was left on the bottom of the tubs. I assume that happened in the sinks too but didn’t pay attention. But now ever since then, whenever we take a shower, the water in both showers will either take forever to warm up and then even when it does, won’t get as hot as it should and will even start to drop the temperature to lukewarm before heating back up again (still not as hot as it should be), or won’t get warm enough to even get in the shower. This has happened every time, but only in the two showers. All of the sinks work fine. What would cause this?

 

[Terry]

How about a picture of the shower valves, or if you know the make and model, that would help too.
It may be something with the cartridges.

 

[Sponsor]

 

[Paulypfunk]

Might have sediment caught in the control cartridge. I’d probably try disassembling it, flushing the water supplies with the cartridge out and then cleaning the cartridge before reinstalling it.