Before I had good water pressure and hot hot water at all faucets and showers. Then, as regular maintenance, I drained and flushed it and a small amount of small brownish particles came out but nothing to cause any alarm. Thereafter, the shower and faucets furthest from the water heater produced only warm water, no longer hot hot. So I raised the temps a little bit and hit the "reset" button. A week or two passed and now the water coming out at furthest end is merely tepid, not even hot. So, today I replaced the heating elements. (yes, with the correct ones.) The old ones were not covered in hard lime although they did have a film of brown, or rust-colored crud that wiped off easily enough.

Now the water coming out of the closest faucet is very hot, but the water furthest away is warm, almost tepid. Now let's add the really odd clicker: The water pressure in the shower closest to the water heater dropped significantly and at the furthest shower dropped to almost nothing, including cold water.

Any ideas?

EDIT: THE WATER PRESSURE ISSUE IS SOLVED. TEMPERATURE ISSUE STILL BAFFLING.



Edited 2 times.

Remove your shower heads and check pressure with them off. It is very likely they are clogged with debris. Also faucet aerators can clog if you notice a loss of pressure or volume.

Pressure was better this morning. Seems fine without showerhead, which is now soaking in CLR. Water coming out of sink is hot, but the shower just 5 feet further from the water heater than that sink is still merely warm.

The debris mentioned in the previous reply is the most common cause of problems after maintaining water heaters. It can clog valves and faucet aerators, causing both pressure and temperature problems. Remove, inspect and clean the valves and filters in all your hot water endpoints.