Here's the situation:
- Almost no hot water pressure (just a trickle) at all outputs (not just a single sink with an issue)
- Cold water runs fine and has full pressure
- Water heater is tank-style and is not leaking
- Water heater was not regularly drained to reduce sediment buildup (and is old enough to likely have plenty of sediment inside)
Here's my rather uneducated guess: that sediment has built up inside the water heater and is clogging the exit pipe.
A repairman from the natural gas company inspected the water heater and said it's an easy repair: all that needs to be done is to clean off the water heater's exit pipe filter screen.
Okay... so I've searched all over the interwebs and I have not found a single site or video showing how to do this, or even if such a filter actually exists.
Is my guess of the cause of the issue a reasonable guess? Is the repairman's recommendation correct? Either way, besides calling a plumber, what's the best way to restore the hot water pressure?