Replaced element in hot water heater; all pipes work except downstairs shower, which barely trickles; shower head is clear; pipes are old how do I get water to work in this shower

Sandra...

Just like you suspected... sediment has been disturbed when replacing the element... SO, Most likely will need to remove the stem and/or cartridge assembly from shower valve to clear this up.

Basically, you will need to shut the water off to shower, remove the cartridge or washers, then you will need to PULSE the water so can clear the valve of any residual debris/sediment (cover valve with rag when you do this pulsing of water on/off).

If need help with this... let me know the name on the faucet and I will see if I can find you a specification sheet on your valve... will make easier to break down and then reassemble.

Let me know... Mark

.