I have a 50-gallon electric hot water heater (for residential use) with two heaters, upper and lower. It is close to 14 years old.
For some stupid reason, I never thought of flushing the vessel for period maintenance. It is protected upstream by a water softening system, but our water is rather hard. I am sure the water softening system is providing minimal protection. Anyway:
I just flushed the hot water heater tonight. luckily, the drain valve opened when I feared it could be so jammed with crud. The water came out slowly, but it was not as murky as I would have imaged. Still, the slow drainage concerns me that the bottom of the vessel could be loaded with crud. (I drained about 12 gallons.) Naturally, the cold water supply valve was closed. However, might I force more crap out the bottom if I leave the cold water supply line open? Besides a potential for burns from being splashed with hot water, what are the risks? Might this help loosen more crud inside the hot water heater than a simple draining of about 25% of the tank volume? Or, might I get more than I bargained for?
Assume I do not perform a “forced flush” as suggested above, the family complains the water is not hot enough. The odds are high the heaters are loaded with scaling thereby reducing the effective heat transfer. Both heaters are set at 125 F. They can go to 150 F. I am tempted to set at least one of these heaters, if not both, at the higher temperature. Again, what are the risks? Is it bad to set one heater differently than the other? And, if no problem, does it matter if I set the lower or higher heater at 150 F? Your thoughts? Concerns?
All thoughts appreciated. And, thanks for trying to keep me out of hot water with the family!
Water heaters take a long time to drain. Even a perfectly clean one is still going to take an hour or two to get every last drop out. Remember, the only pressure is the weight of the water above it, you don’t have the city pressure behind it that you’re used to seeing.
You can routinely drain 25% if you’d like, in fact, your manual might even suggest you do just that every month or so.
You can also turn the cold water on while you’re doing it, but I’d suggest draining it all the way down, then running the cold water so any crud that get’s picked up just flow right out the drain instead of getting mixed back in to the entire tank full of water which result in the ‘regular’ amount of crud coming out (it would be just as mixed up as it is when someone takes a shower).
Don’t turn the water up to 150, someone will get hurt eventually.
If the water doesn’t seem as hot as you’d expect it to be, most likely the lower element or lower thermostat isn’t working. They’re both very easy to test and very easy to replace. But have to be done correctly or you’ll end up with other issues.
Lastly, you can get cheap boroscopes pretty much anywhere now. You can drain the tank and either remove the spigot or an element and look inside with a camera (you might even be able to see in with just a flashlight at the lower element hole) and see for yourself how much crud is in there.
Just had to replace the heater in my Mothers house after 10 years–nearly ruptured the plumber when he went to pick it up, it was full of sand! If I last as long as the new one, I’ll be happy
If I had a 14 yr old electric water heater, I would replace it before a potential catastrophic leak. Your anode rod has probably deteriorated meaning electrolysis will eventually destroy the liner resulting in a slow or more serious leak.
Heck yeah. Along with that, I’d consider replacing the heating elements and thermostats. The old ones are probably caked with scale and not heating efficiently anymore.
On a scale from 1 to 10 of “DIY difficulty factor”, I’d rate anode rod and element replacement at about a 2. It’s really quite simple. The hardest part is breaking the old anode rod loose, because they are tightened down very firmly. Slip a length of hollow pipe or something over the handle of your ratchet to lengthen it and increase your leverage, you’ll need the greater mechanical advantage.
Needless to say, shut off the heater and the cold water and drain the tank fully before you do any of this.
There’s a 28 year old gas water heater at my house. I keep thinking it surely must need replacement, but it still works and it still doesn’t leak. Zero maintenance has been done, although it a Rheem and the sticker says something about a glass liner.
I don’t mean for this to be a hijack, but since we’re on the subject… we have a propane water heater. It was installed in 1989. Amazingly, there has never been any PM done to it and it still seems to work O.K. Will I get better efficiency if I drain the crud out? Should I attempt it? I’m sure one day it’s going to fail and leak. Should I just go ahead and replace it now?
Does it have a protective pan under it or is it located somewhere where a leak won’t cause significant damage? Because if a leak won’t cause significant damage, might as well just replace it when it finally leaks. You won’t get better thermal efficiency but you might get more usable hot water if you could clean it - does it provide adequate hot water?
It’s not that they’re tightened down that much, it’s that they’re corroded in after a dozen years of sitting in hot water. I’ve tried a few times to get mine out. The first time it was only a few years old and even then, with a cheater, I couldn’t break it free. Also, once you start cranking on it that hard, you have to have someone else giving it a giant bear hug or the entire tank will start turning.
I just tried again a few weeks ago with an impact driver. But even after about 30 seconds of that and I stopped before I broke something.
I have seen a tool just for doing it. It’s a force multiplier (a ‘standard’ socket attachment with some gearing to multiply your input a few times), but it also has a way to brace itself against the plumbing so it doesn’t just spin the entire heater.
Now that I think about it, it may have been a one-off tool that someone made.
If swapping the anode rod is something you want to do, your best bet is probably to loosen (and check) it and retighten it once a year or so. Or just remove it and use an electronic one instead.
I’m lucky with mine. My last one ruptured in the middle of the night. Luckily I happened to be away and heard it. I don’t know exactly where the water was coming from, but it was just hitting the steel jacket, running out the bottom and about 3 feet to the floor drain. I shut off both valves, the gas and went back to bed. Everything was dry by morning. In retrospect, I should have attached a hose right away and started draining it, but I didn’t realize how long it would take and frankly, I was trying to just take care of it and get back to bed before I was too awake to fall asleep again.
The nice thing about using propane is that I assume the tank is on the other side of that cement block wall. Tankless will save about 30% of the fuel and you won’t run out of hot water. And as you can see they are inexpensive. Tons of people DIY install them, and you could install yours against the cement blocks. You just need to maybe buy slightly longer hoses when you replace the hoses anyways for the gas supply, cold water feed, and hot water feed.
Reasons *not *to do tankless : for hydronic heat systems, if the existing electric or gas infrastructure can’t supply the high rate of electricity/gas needed, if you have a use case where you want a supply of just a trickle of hot water. Since propane gas is more energy dense than natural gas I bet that won’t be a problem. Oh, and if there’s no electricity supply to the place you want to do the heater installation.
I view the downside of a hot water heater failure as pretty catastrophic, so I don’t play around with fixing them. I’ve owned two homes with 10 year + water heaters and my insurer was unwilling to insure against their failure. I replaced both of them for about $800. Not cheap, but I think it’s worth the money over hoping that they don’t fail (without insurance) after my attempt at fixing it.
Aside - Pan under the hot water heater: I’ve seen these pans at the Home Depot or Lowe’s website, and they seem ridiculously shallow such that you’d need the tiniest of leaks to buy one any time (or CY one’s A)! Am I wrong?
Thanks, all for your thoughts. We’re going to replace the hot water heater, and I will PROMISE to do routine water changes on it. BTW, need a laugh? The Dept of Energy website that offers advice on hot water tank heaters says to drain a quart every three months! Ha! Even though this is general advice for no specific hot water tank heater, even for the smallest tank (typ. 30 gals IMHO) this would be absurd! Maybe a quart if your system is 1 gallon!
When mine ruptured, it wasn’t that bad. It was just water pouring out the bottom. I believe they’re really meant in case the T&P valve opens, which would only be open for a few seconds. Possibly over and over if there’s a problem, but just to release some of the pressure and/or get enough new water in to cool the tank back down. If the T&P valve or drain spigot start leaking just because they’re going bad, it likely won’t be a fast leak anyway. Even in the case of a rupture, it’s really just to buy you some time to shut off the hot/cold water (which will substantially slow down the leak), get a hose connected to the drain and start emptying it. Keep in mind that the catch pan could be 2 feet bigger than the water heater and 4 feet high, but if it fills faster than it empties, it’s eventually going to overflow if you don’t deal with it. If you really want to be safe, stick a water sensor in it so an alarm goes off if there’s a problem.
I didn’t watch the rest of the video, but here’s an example of a fairly substantial, but perfectly containable leak.
24 years is a very long time for a water heater. I’d be surprised if this one outlasts a new one (call it 10-15 years). Personally, I would just leave it, especially if it’s in a place where it won’t do any/much damage if there’s a problem. If you want to be proactive, you could replace it, or even just start planning to do it in the next year or so. Budget for it if you need to and keep an eye on sales and/or energy rebates.
I’m surprised (looking at your link) at how cheap it is for gas. When I’ve looked, the electric ones are about $500ish, but the gas ones can easily be 2-3 times that. However, one of the big issues is venting them. They often can’t use the same vent that your current gas water heater uses which means even the typical DIYer ends up having them professionally installed.
That seems…odd. I suppose emptying such a small amount, if done every.single.month, will help to prevent sediment from building up in the first place, help the homeowner to not end up in a situation where the valve doesn’t close and give them a chance to notice if there does happen to be a lot of sludge pouring out.
But, if you were to start doing that 10 years in, it probably wouldn’t do much at all.
The other possibility is that they meant ‘a quarter of the tank’ and not ‘a quart of water’.
