All this talk of water heaters, I may as well add some of my experience, recent and ancient.
We just had our water heater replaced when I got the furnace and A/C done this season. This water heater was the original in the house, mfg date of 1986! I meant to replace it 15 years ago, thinking it was at end of life, and could go any day. Procrastination paid off once again!
I recall we had a strong rotten egg smell after we moved in (1992). We are on private well with water softener. I don't recall the details, but this problem can be triggered if the house has been unused for a few weeks (which it was), and I'm pretty sure I replaced the anode with the one recc for this problem (aluminum-zinc rather than magnesium?). I also decided to replace it many years later, realizing that they do get eaten away over time (they are called sacrificial anodes), but the old one was sooooo tight, I decided I might break something if I torqued any harder on it, so I left it.
Now I'm reading in these sources, that softened water aggressively eats away these anodes. But, I had the same anode from 1992 to 2016, surely it was gone for many years, and no problems?
So after the new one was in for 3 months, we suddenly got strong rotten egg smell. Hmmm, I'm thinking the installer should have asked, and installed the aluminum-zinc one to avoid a call back on this? But I figured since it happened so suddenly, I would try the 'quick fix' of adding bleach or hydrogen-peroxide to the tank, and see if that helps. I just used bleach, and to avoid unscrewing the anode or inlet/outlet, I just shut off the cold water valve at the inlet, and then opened the COLD water tap at the laundry sink (which was conveniently on the water heater side of the shut-off valve). Next, I held a cup directly up to an upstairs faucet, poured a bleach water solution into that, and opened the HOT water side. This sucked the solution into this faucet, and into the tank. I used about 1 cup of bleach total (probably too much), and after a few minutes, followed up with a couple quarts of clear water to get all that out of the pipes and into the tank. Closed the faucets, opened the valve to the water heater, and did a quick flush of all the faucets in the house to get the air and any loosened gunk out.
So we had a pretty strong bleach smell (like going to a swimming pool) for a day, and no rotten egg smell. Just to be sure I followed up again with 1/2 Cup bleach two days later. It's been 2 weeks now, and no return of the rotten egg smell, so maybe we are OK?
Reading about the T&P valve here, I realize I could probably suck bleach water in through that while opening the drain valve - then I wouldn't need to run up/down stairs or enlist DW to open close the faucet. Would need to open the valve first into a bucket to get the air out so it could siphon back.
On a semi-related note, these 'rotten egg' references also mentioned that if you have a bad smell at one faucet, it could be 'nasties' in the drain. Well, I have had intermittent issues like that at one drain, and never really find the source. Then one of them mentioned the overflow drain - of course! That gets gunk in it, and rarely ever gets flushed out. So I've been getting some bleach solution down the overflow port, and I think that is doing the trick there as well.
-ERD50
). If a threaded neck is cracked (or, more likely, the nipple is corroded), a leak could become a gusher very quickly and you'd want to know about that right away.
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