Iron pipe or plastic of some type?
How old is the WH?
I would say the WH is plugged at a quick guess.
If iron pipe though could be a rust plugging issue.
Does water come out of the WH drain when you open it? And at a continued flow?
if so the problem is in the outlet of the WH or the associated plumbing.
I would shut off the gas or electric to the WH before testing/draining to avoid explosions, death that kind of undesireable events.
Also be sure the WH is completely filled before restoring the power/heat source.
Copper, electric don't know how old, we've been here 5 years. I guess I'll have to flush the WH tomorrow, hopefully that will fix the problem. I'm wondering if I can back flush from the washing machine hot water feed to clear any possible blockage at the feed side of the valves.... Older plumbing system, house built in 1972, don't imagine there will be a back flow preventer in the older system.
This might be a good time to replace the old gate valves with ball valves but will have to buy a new "torch", the old one went bad last year.
I've also been considering replacing the WH with a tankless system.