The hot water in the shower seemed to be kind of wimpy, which is to say that it wasn’t very hot. The temperature ranged all the way from lukewarm on the one extreme to tepid on the other. My ever-loving wife, “Paris” (not her real name), is not one to complain but she made it clear that it was not up to “Hilton” standards. I turned up the temperature dial on both water heaters from the “A” position to the “B” position and then to the “C” position but it didn’t make much difference. Every once in awhile, the shower would put out a brief burst of water that was actually hot. This made me think there must be a blockage somewhere in the hot water pipes or the water heaters.
I did a little reading on the subject and apparently you are supposed to drain hot water heaters once a year to flush out the sediment and corrosion in the bottom of the tank. I calculated my water heater flush rate: number of years in house: 5; number of times flushed: 0.
I was a bit behind schedule.
After turning off the power to the water heaters so that the heating elements wouldn’t burn up in an empty tank, I headed downstairs to do some flushing.

You are supposed to be able to hook up a garden hose to the hose bib at the bottom of the tank and just open it up and let the grungy water drain out into a floor drain or bucket or outside. That is what you are supposed to be able to do. But the Einstein who installed the water heaters used drain pans that are so small there isn’t room to get a hose connected. So I had to let the water drain directly in the pan, which is connected to a PVC pipe that goes outside. The purpose of the drain pan is to collect any water leaking from the water heater and send it outside rather than flooding the house.

That same genius installed the PVC drain pipe from the drain pan going uphill to the pipe going outside. This meant that the drain pan had to be almost full of water before any of it would drain outside. How does this stuff ever pass inspection?

The PVC pipe went through the outside wall but the outlet tube just dumps the water in the carport where I keep a lot of my “valuable property.” So I connected a shop vacuum hose to it and put the other end out in the yard.

The water coming out of the hose bib didn’t look that bad but it didn’t really come out as forcefully as I expected. It was kind of gurgly. (It’s a word, look it up.) Opening the pressure relief valve let more water flow out from the tank but it was still uneven.
To shake things up I closed the hose bib and then opened and closed the shut off valve on the top of the water heater that lets in the cold water. Then I drained more water while working the pressure relief valve. I repeated this about 10 times. The water was a little browner. One more blast of water from the inlet valve and all of a sudden, KA-WHOOOSH!!! Water exploded everywhere. After shutting off the hose bib as fast as I could and drying myself off, I looked at the rusty water in the drain pan and concluded the obvious: the water heater was no longer plugged.
I drained some more rusty water out of the tank but it took so long due to the uphill PVC pipes that I gave up and turned it off. Then I went upstairs to the kitchen sink and turned on the faucet. Brown water. I let it run for a while. And run some more. I ran that faucet for 2 hours before the water was clear. The other hot water faucets in the house had to be flushed for about 5 minutes each to clear out the rusty water.
How’s the shower? Hot. Very Hot. I turned the temperature control on the water heaters back down from “C” to “A” and the water is still plenty hot. Of course my opinion is of little consequence so I asked my ever-loving wife what she thought. Paris said, “That’s so hot right now.”
I’m thinking I might flush the water heaters more often than every 5 years from now on.