[Shop-talk] well that can't be good...

[Randall]

> the question is: what do I do now? I just closed the valve, just in case,
> but it seems to me that this is probably not a Good Thing.

Not tried it on a water heater, but it's a common operation on Triumphs ...
open or remove the valve and stick a length of stiff wire into the hole.
Poke & prod until it works through the crud.  I've even used a drill bit
(turned only with my fingers, so can't cut into sound metal) or a dental
pick.

But honestly, if your water heater is that far gone, it's probably time to
replace it anyway.  There may well be other openings that are only clogged
with sediment & rust.  And discovering that your old heater has been leaking
for hours or days unnoticed; followed by not having a hot shower until it's
replaced is an experience I'd rather not repeat.

Randall