This is the page of the thread where we actually address the OP's question, and nothing but that.

quote:

Originally posted by ZSMICHAEL:
Besides saving energy does a cooler temperature on the heater prolong its useful life?

Let's look at this assuming 'useful life' = time it's actually heating water (gas or KW on). For argument's sake, let's assume you take your showers at 100F and the water heater is set to 100F. You're using water straight from the water heater alone. If you set the water heater to 120F, you're using a mix of hot water and cold water to take a 100F shower, so it's not having to use as much hot water. I know this is simplistic and doesn't account for how much water to reheat back to xxx degrees. Also think about your dishwasher. What does the dishwasher's manual say about the water temperature you should be using to properly wash and sanitize your dishes? A Copilot Search said between 130-145F. If you are pumping in 100F water, it may cause your dishwasher to turn on electric coils in the bottom to heat the water, adding more electricity $$ to washing your dishes.

No matter hotter or cooler, I believe maintenance plays a big role - draining/flushing periodically to remove built-up mineral deposits and replacing the anode rod per the manual.

Several websites I looked at generally said this: "You should set your water heater temperature between 120 degrees to 140 degrees Fahrenheit. If you set your temperature any lower, you might risk contaminating your water supply with bacteria. For temperatures above 140 degrees, you risk experiencing severe burns. Generally, it is recommended that you set your water heater temperatures at 120 degrees Fahrenheit."

Hope this helps. A number of factors go into determining the useful life. The gas hot water heater we inherited when we bought this house lasted over 25 years.

quote:

Originally posted by RogueJSK:

quote:

Originally posted by darthfuster:
My plumber friend says you can extend its life by preventing or removing sediments. I’ve never been that into it enough to flush one out

It's not hard. I do mine once a year, in the fall. Takes about 45 minutes total to drain/flush, but less than 5 minutes of that is actual work on my part.

It's worth the few minutes a year to extend the heater's lifespan.

So many questions:

Is there an optimal time of year to perform a flush? For example, my county's water service changes their chemical additives in April and May ostensibly to kill bacteria (it makes the water taste terrible), would it be helpful to time a flush around this period?

Should the heater be turned off during the procedure? I would imagine that exposing the heating element (electric heater) and/or thermocouple to the air while power is on might not be good for it, Chernobyl anyone?

Is it best to turn off the water heater some time in advance so as to let the water inside cool before flushing?

Is there any advantage to putting some kind of additive into the tank for some period of time before flushing?

Is a partial flush (like of the bottom 1/3 of the tank) effective (assuming that the sediment accumulates there)?

Does watching the outflow, and stopping when the water runs clear a useful practice?

Should the cold water inlet to the heater be shut off before the flush?

WRT the anode:

Can you tell just by looking whether it has reached the end of its useful life? If so, what should one be looking for?

Is there some kind of test that can be performed without removal (e.g. electrical resistance)?

architect - There are youtube videos on flushing, and both shutting off pressure and draining and letting it run with system pressure are options.

I do mine with pressure after it has cooled from being away and on vacation setting. That is mostly because there's no reason to flush out heated water. Partly from a thrift standpoint and I have run a hose into the grass to flush and don't want to kill the grass.

If your water heater is working, there isn't much reason to replace it. If it starts making noise, leaks, or doesn't provide the capacity it used to, you might want to replace it. It is just a reservoir with a thermostatically controlled burner. Not real complicated.

If you live in an area with hard water, as sediments accumulate, it will become less efficient. Flushing will reduce sediment accumulation, but won't prevent it. Sediment accumulation reduces efficiency and messes with the timing of burner running because of the sediments insulating properties. Imagine a burner acting on a steel tank, then imagine the tank with an inch of lime deposits between the tank wall and the water.

I know some tanks are what they call glass lined, which I suppose means porcelain coated. This is meant to prevent corrosion but it can have defects or develop cracks. Sometimes the reservoir rust through and leaks and the heater is done. You've got (if gas) a burner/pilot/thermocouple and a gas control with a thermostat and overheat protection. The burner assembly and control can be pretty cheap to replace if you know what you are doing. There are youtube videos that explain the function and how to work on them.

quote:

Originally posted by architect:
Is there an optimal time of year to perform a flush?

No. But you probably don't want to do it during the middle of winter when it's below freezing, because you're going to be draining 40-50 gallons of water into the street/yard/etc.

quote:

Should the heater be turned off during the procedure?

Yes. If electric, turn it Off. If gas, put it on Pilot.

quote:

Is it best to turn off the water heater some time in advance so as to let the water inside cool before flushing?

You can, but I typically do not. My heater is in a garage closet, so I hook up a garden hose and run it to the street gutter. I'm not ever coming into contact with the hot water.

quote:

Is there any advantage to putting some kind of additive into the tank for some period of time before flushing?

No.

quote:

Is a partial flush (like of the bottom 1/3 of the tank) effective (assuming that the sediment accumulates there)?

Might be better than nothing, but won't be as effective as a full drain and flush.

I drain the entire tank in order to remove all of the sediment I can. And then flush it to remove most of anything left.

quote:

Does watching the outflow, and stopping when the water runs clear a useful practice?

No. Again, I just let mine drain completely, while I'm off doing other things.

Besides, I never have noticeably dirty water draining out anyway. The minerals I drain from my heater are very fine calcium crystals, like tiny grains of white sand. You can't see them at all when the water is flowing from the hose. It's always totally clear. But you can see them once enough of them start to collect in the nooks and cracks of the concrete gutter as the water flows over it, kinda like panning for gold.

quote:

Should the cold water inlet to the heater be shut off before the flush?

Yes. But once you drain the tank, you'll then open the water inlet on full for a short time, using this inrush of water to flush any remaining sediment from the bottom. I do this a couple times before I finish up.


My usual method is:

1) Turn gas heater to Pilot. (Or turn off power, if electric.)
2) Turn off water inlet using valve on top.
3) Attach water hose to drain valve on front bottom and unroll hose down the driveway to the gutter.
4) Open drain valve.
5) Go inside and turn hot water faucet on the sink in the bathroom that's furthest from the heater all the way on (to break the vacuum and speed up draining).
6) Go find something else to do for ~45 minutes, until there's barely a slow trickle coming from the end of the hose
7) Open water inlet on full for ~10 seconds, then close.
8) Wait a little bit for hose to slow to a trickle again.
9) Repeat opening water inlet on full for ~10 seconds.
10) Wait again for hose to slow to a trickle.
11) Close drain valve.
12) Unhook garden hose.
13) Open water inlet.
14) Go inside to the sink with the open hot water faucet, wait for the faucet to stop sputtering air and run fully, then shut off the faucet.
15) Wait ~15 minutes to allow tank to refill with water, then turn the heater back on to the normal temp setting.

Done. A couple minutes of work at the start, a couple minutes of work at the end, and 45 minutes of waiting and doing other stuff in between. Then you're good until next year.

If you're still confused, there are a ton of tutorial guides and videos on draining water heaters out there.

quote:

Originally posted by oldbill123:
And buy one from the pro plumbing shop not a box store

This. When I was young I bought them from the big box stores and replaced them myself. Every few years they would rot out. Nowadays I call a solid plumber and pay real money for a high quality unit that I won't have to worry about. Come to think of it, the last one I had installed is still running, past its normal lifespan. If it were a pos it would have been gone long time ago.