electric water heater on timer? Bad idea?

Jim S. · #21 04/25/07, 02:52 PM

You are absolutely correct. It does not pencil out in the real world, but people think that it does. The payback on a $40 timer would be 10+ years...longer than the usual life of most home water heater tanks. You are correct on the blanket, correct on the tankless (though I have also seen that they have shorter lifespans, plus higher initial cost -- so all savings are in the short-term). Thanks for the straight answers.

To add my .02, the best way to save a little money on heating water is to turn down the thermostat(s) and use just the hot water faucet only for hot water, instead of diluting it with cold. My MIL does this at her farm. I believe she has hers at 100-110 degrees, with a 40-gallon tank. I think warm water like that sux for showers or baths, but she is used to it, and it does save some money without adding any cost to buy anything else. Plus, you have zero scald risk, which is nice if you have young kids or older folks in the household.

Quote:

Originally Posted by Micahn

This post may be unpopular with a lot of people as it is going to tell the truth instead of a lot of myths like has been posted.

I was a plumber for over 20 years and even took over my fathers company until I got hurt and could no longer work. I was lucky growing up as my father was also a master plumber and was willing to pay for any school I wanted to go to so i could better myself. I decided to be a plumber like him so went to any school I could find related to he field. I could have a wall lined with diplomas that would make any doctor hang his head in shame. I even went to the NASA school for solar way back when they had it.
After I got hurt I was a instructor at a plumbing apprenticeships school for a few years then became the coordinator for it (same as lets say principal)

Anyway here it goes related to this topic.

Your best bet if you want to save money would be a tank less water heater. It should not cost any more then a standard water heater in most cases depending on the size you need.

A water heater blanket is about the worst thing you can do to a water heater. A water heater if it is off for some reason can sweat a little because of the cold water coming into it. If a blanket is used it will hold that water on it and will cause rust to start forming. Rust can cause all kinds of problems with water heaters. It can cause the joints at welds to start leaking is the main one. That would mean buying a new heater.

Depending on the age of your water heater a timer might be useless. If it is say under 20 years old chances are it will not save you much at all. If it is older then that the insulation chances are is not all that good and a timer could help you out some. I would set it to run a hour before you need any hot water and run about a hour after. Chances are it would hold enough heat over night to wash up in the mornings but would depend on the size really the bigger the better.
a Modern water heater will hold that heat for days if the power or gas is off. Sure it will go down some but I have seen hot water come from a heater that the power was off for 3 or 4 days.
Now if your going to be away for a few days by all means turn it off as it would just be wasting power. But if your there every day and your heater is newer chances are it would take years to save enough to even pay for the timer.

Oh almost forgot, A tank less one would work fine on well water as long as the water is not all that bad. Your heater now is ok right ? A tank less heater works in the same way just does not have the big tank with it. Plus it has a sensor that says ok water is moving time to turn on. If you water is real bad you should have some sort of filter on the whole house anyway to keep what ever it is down some anyway. It could be anything from sand to any number of things that could be filtered out easy to make your water much better for you and your plumbing system.

anniew · #22 04/25/07, 03:20 PM

I turn my water heater on and off at the circuit breaker. Normally, I turn it on when I get up and off after it heats ups (about a half hour or so--a 40 gallon tank.
But I think I get the most savings by running it at the off-peak hours, since I have a day/night meter where the night rate is about one-third the day rate. So the night rate is from 8-8 during Eastern Time and 9-9 during Daylight saving time. I turn it on only (except for unexpected things) during the low rate. The low rate is not only nights during the week, but all day and night on Sat. and Sun. If you plan to do your stuff using electricity either evenings or weekends, that saves a bundle. My normal electric bill is $40-50 a month. I have no washer/dryer, but do have four small freezers, and fans for the greenhouse. Ann

Wolf mom · #23 04/25/07, 08:22 PM

I am stunned to hear that the payback on my timer is 10 years when a water heater is what, the second/third(?) highest household item in electricty use. Especially when the usage is cut to 4 or 5 hours a day rather than 24.

Maybe the question to ask is how long does the water stay hot before the heater needs to cycle on & for how long does it run (in a newer heater) to (re)heat the water.

A question: why would one want to buy a tankless water heater if you've got to go buy a water softner & just think of all that salt that has to be bought & is then being added to our underground water...(I'm sure this question shows my lack of understanding)

TexasArtist · #24 04/25/07, 09:02 PM

I put a timer on my hot water heater and the bill dropped 85 bucks. My timer looks like a clock with alot of little holes on it where you can put some pins that come with it. I have it come on for about a half hour before I get up and then about an hour before dinner. If I'm going to go away I take the pins out and it doesn't come on at all.

morrowsmowers · #25 04/25/07, 09:20 PM

I would use a standard, tank type water heater with either the timer or an on/off switch that you control. The timer is nice because it can be set to come on when you are asleep or not home and hot water is waiting for you but the switch option is simpler and cheaper and gives you infinite control while you are home.

The timer that was shown with a pilot light means it has a small light on the timer that comes on when the tank is powered so you know that you are making hot water. If the light is off the power to the tank is off.

If you go with a tankless heater you will need a large electric service to support all of the amperage that will be needed, as well as a whole house filter and possibly a softner system as well, depending on your water.

I am a plumber by education and an engineer by trade so I also have professional experience behind my "opinion".

Ken in Glassboro, NJ

strider3700 · #26 04/26/07, 01:33 AM

does anyone know of a timer that can have two different programs entered? My programmable thermostat for my electric baseboards allows me to enter a different program for each day of the week. I'd like to be able to do a weekday program and a weekend program.

A timer should come in really handy since we mostly shower at night and I'd like to get solar heating going as well. Let the solar heat all day and then the timer kick on to top us up if needed.

Tankless is not worth it since I have no propane or gas in the house. All electric tankless would require a new panel since I'm at 125 amp and thats the max I can go to.

Junkmanme · #27 04/26/07, 04:48 AM

Regarding laundry..........:

.."If I want to do all my laundry in one day or whatever, I can override the tabs by just pushing an on/off lever without touching or resetting the tabs...."

I only do laundry with cold water. Works fine for me.

just a $ saving idea.
Bruce

painterswife · #28 04/26/07, 07:04 AM

"A question: why would one want to buy a tankless water heater if you've got to go buy a water softner & just think of all that salt that has to be bought & is then being added to our underground water...(I'm sure this question shows my lack of understanding"

I would have a softner wether I had a tankless or not. If I don't I have a crust on everything and it ruins my clothes and fixtures. Not to mention the red iron that the softner removes.

"If you go with a tankless heater you will need a large electric service to support all of the amperage that will be needed, as well as a whole house filter and possibly a softner system as well, depending on your water

Not it is is propane.

Jill

saramark · #29 04/26/07, 07:09 AM

We manually turn the heater on/off, lowered the thermostat to a non scalding temp for kids safety, and use cold water for the laundry. The dishwasher has a temp booster so that is not an issue as long as the water comes in above 100, which I have it set at 110

mark

pixelphotograph · #30 04/26/07, 07:32 AM

we've had the timer system ever since can remember growing up. We have a family of 3 and have never had a problem with not having enough hot water.
Yes it saves money and it saves the life of your hot water heater and it saves electricity not heating water up all day and maintaining it that way.

saramark · #31 04/26/07, 07:40 AM

Why do we call them "hot water heaters" anyway. They heat COLD water, not hot, right.

NWoods_Hippie · #32 04/26/07, 07:45 AM

Up here on well water, which is quite hard, I have three friends who have Bosch tankless water heaters, all run on propane. They have had these tankless heaters for well over 5 years and have never had a problem and none of them have water softeners.

Per the Bosch website you can get a $300 rebate on your 2007 taxes if you purchase a tankless water heater this year. My landlord is planning on installing one here at the farm I rent, and I can't wait!!

Margie

saramark · #33 04/26/07, 07:50 AM

My friend installed a tankless run by propane and he loves it. It seems to take forever to get hot water when you turn the faucet on. I realize there is alot of line between the heater and the faucet, but it seems to take longer at his house.

mark

NWoods_Hippie · #34 04/26/07, 08:13 AM

Mark,

I think that would make a difference, at my friend Kim's the tankless is on the first floor between the kitchen and bath, hot water in an instant! Also Kim has the "single person" size but I have washed dishes at the same time he is taking a shower and there was plenty of VERY hot water for both of us.

The hot water heater is in the basement of my big old farm house, and it takes forever for the hot water to get up to the bathroom on the second floor, so I am already used to waiting!

Margie

artificer · #35 04/26/07, 10:16 AM

I've been interested in this topic from some time, (tankless vs electric/propane tank) so I did a couple of "back of the envelope" calculations. Using the info from Lowes for their 50 gal energy smart water heater , this is what I came up with.

Surface area is about 28 square feet.
R10 for 2" foam insulation, and I guessed at 1" fiberglass, R3 for comparison with older style water heaters.
100 deg F and 140 deg F water temps in a 55 degree basement

Using this information, it takes the following energy to keep the water warm for one day:

100deg 140deg
.89KW-hr 1.7KW-hr 2"foam insulation
3Kw-hr 5.6KW-hr 1" fiberglass insulation

At $0.10/KW-hr, the costs are $.09, $.17, $.30, $.56
Using an average 30 day month, the costs are $2.7, $5.1, $9, $16.8

With this information, I would say a timer makes sense. Even the best insulated tank kept at a low temp will have a payback time of a year and a half. The worst is under 3 months. (based on a $45 timer you install yourself) If you have metered power, it makes even more sense.

This is all theoretical, but should give a good indication of what costs could be. If you are going to do this, I would get the best insulated, smallest water heater I could find. It doesn't pay to have a monster 50 or 70 gallon heater to heat just enough water to wash dishes. A long, hot shower s for several people, however... I guess this is where the tankless heaters get most of their efficiency advantage.

Micahn, I would disagree on the heater blanket. The water would have to get down to below air temp to cause condensation. If you haven't drained the tank and refilled it with cold water, it will not cause condensation. People are talking about still having some warm water to use after its been off all night. On the newer units they use spray in foam insulation. It seals the heater, so even if the tank is fully cooled, you will not get condensation. I can see how it could have been a problem on older heaters, however.

The Paw · #36 04/26/07, 10:59 AM

I can't see the sense, personally.

Based on artificer's calculations, a well-insulated tank results in monthly heating costs of $2.70 to $5.10. I am not sure how much a timer reduces that.

If you are not getting much heat loss with the power off, then the thermostat will be keeping the element off most of the time anyway. And whatever heat loss you do get, means you have to heat the tank back up from that point when you switch on. In other words, you can either keep it warm with a little juice at a time, or use most of the juice in one shot as you reheat.

I would be surprised if you could reduce the energy consumption by more than 25% with a timer (if that), which would be a savings of a dollar a month.

Rather than putting money into a timer, I think investing in improving insulation on the water heater and adding pipe wrap to hot water lines would yield better savings.

SolarGary · #37 04/26/07, 11:03 AM

Quote:

Originally Posted by cc-rider

Where is the 'break even' point? If I only use hot water for a short time in the evening (showers, dishes, laundry), would it make sense to have the water heater on a timer and come on at, say, 5:00 and go off at 10:00? It'd still be warm enough for a quick hand-washing in the morning before work, I'd think.

Or would it use more energy having to heat it all back up every night than it would to just keep it going all day?

I'm thinking a 40 gallon electric water heater, well insulated.

Other option was a tankless version, but with well water, I'm not too sure I want to do that. Plus the installation cost!

CC

Hi,
The good electric water heaters these days have energy factors around 0.95

To me, this means that the standby losses are 5% or less, and this is the maximum saving you could achieve with a timer.
Maybe I'm missing something?

Gary

Micahn · #38 04/26/07, 11:40 AM

Quote:

Originally Posted by artificer

Micahn, I would disagree on the heater blanket. The water would have to get down to below air temp to cause condensation. If you haven't drained the tank and refilled it with cold water, it will not cause condensation. People are talking about still having some warm water to use after its been off all night. On the newer units they use spray in foam insulation. It seals the heater, so even if the tank is fully cooled, you will not get condensation. I can see how it could have been a problem on older heaters, however.

Well over the years I would say I have had to change at least 100 or more heaters because of rust that had eaten the seams enough to cause leaks to start. Most times it is around the elements that the leaks start (the welds around them).
Now all of my time as a plumber was here in Florida where it gets rather hot and all so that might have made the difference. But every time I have worked on a water heater that they had added a blanket to it had rust both on the outside of the covering and inside on the steel tank as well. I had many people try to get me to install them when I was installing their new heaters and I always refused and tried to talk them out of putting them on. Believe what ever you want they cause much more damage then help in modern water heaters.

Here is another little tip for helping to keep the water in the heater hot longer. If the piping coming out of it is over lets say a foot long try insulating it. If you feel them pips you will feel that they are warmer then the air. On a modern water heater they will loose more heat on the outside piping then they will from the tank itself.

WisJim · #39 04/26/07, 01:54 PM

Regarding payback of expense of a timer, I am the kind of guy that keeps track of what things cost, and how much energy I use, and my timer on an electric water heater saved me between $2 and $3 a month, varying throughout the year. Since I used the timer for 8 years or so before replacing the water heater with a propane one, and the timer cost less than $40 by the time I installed it, it certainly did pay for itself.

Kevingr · #40 04/26/07, 03:06 PM

I have off-peak electric on two hot water heaters, not sure the size, one is about 5 feet high and 2 feet across, the other is half that size, they are both over 20 years old. I pay .0399 cents a kwh and my bill is between $5-8 a month for a family of 4, plus the occasional weekend guests.

Basically the heaters are on overnight and off during the day, if we have a lot of guests over and run the dishwasher a couple times we'll run out of hot water by evening. We need more storage capacity. I think the big savings in the timer theory is if you can switch to an off peak rate, but that usually means another electric meter.