Played WoW for a while, then I turned my attention to the water heater. As mentioned last weekend I tried to take a hot bath but the water wasn't all that hot, so today I went downstairs to drain it.
Shut the tank supply off, put the thermostat on "PILOT", opened the drain valve...got a trickle. Shut the water off, opened the hot valve at the utility sink, still a trickle.
Disassembled the drain valve on the water heater. The flow of water was so slight that water was dribbling straight into the hose. Got some wire and probed at it--
GUSSSSSHHHHHH a stream of red, rusty water shot out of the valve, actually surging like arterial blood because of back pressure, and it took me a few seconds to realize that I'd set the valve components atop the water heater when I went to get the wire. A few moments later I'd gotten the valve back in place, but now the heater was gurgling and I could hear the water flowing steadily through the drain hose. Went around to the sump, where the hose goes, and saw steady, full flow into the sump. Clear, now.
Anyway, a lot of sediment--as expected--and rust was splashed all over the place under the stairs where the water heater is. Went upstairs and opened the cold valve in the kitchen sink, and then I sat in the desk chair downstairs and listened to the entire water supply of the house draining into the sump pump.
"It should only be the hot side," you say, and I agree with you. The problem is the unused shower: I never did replace the cartridge in there, so if the hot water side is empty and the cold water side is under pressure, cold water seeps across it and backfills the hot side.
After perhaps ten or fifteen minutes, the flow stopped. Closed all sink valves, turned the water supply back on--and I could hear water flowing into the tank even with its supply valve closed--and then opened the tank supply valve. Clear water coming from discharge, so I closed the drain valve. Opened the hot valve at the utility sink and let it run until it was mostly water, then closed it, went upstairs, and opened the hot valve at the kitchen sink. Let that run until no more air came out. Cold side didn't drain down as far, I got a little air from it but not much. Went to the bathroom and ran full hot in the tub and opened hot valve at that sink; when the air stopped coming I closed them.
Went downstairs and lit the pilot light, then set it to "ON", and it started heating. Looked at the thermostat and tweaked it upwards, just a hair, because even before all this, the water had been not quite hot enough.
Anyway, tried to play WoW but was too sleepy, so I had a nap; and when I got up I washed the dishes in water which was almost too hot. When I let it run on my forearm it was too hot to do that for long--not scalding, but a mite painful. So that'll do, I think.
I am kind of concerned with how much crap was in that water. This is the first time that I've managed to do a full drain on the thing, though, and I did get a lot of rust and sediment out of it. I guess we'll see how that goes. But the water is hot enough, now, anyway.