Electric Water Heater Timer. Mechanical or Electronic ?

[Clarence Martinn]

Which is better? Got the Bradford White 40 gallon electric water heater installed and it is running great. Only problem is that it cycles on and off once about every 30 to 60 minutes. Runs for about 5 or 6 minutes and shuts down. Must be doing that to keep the water up to temperature. Well, we only need the hot water to wash dished in the dishwasher and to take bathes . The dishwasher has a built in 4 hour setting on it , that allows it to start up 4 hours after you press start. The only other use for the hot water ,is for baths. Figure that if the timer was set up to run the water heater from say, Midnight, to about 3 AM. There would definitely be enough hot water for a quick bath or shower in the day time.

Eventually, we plan to go on the cheaper Day Night electric rate . The night rate is 2/3's the cost of the Day rate. Night rate being 11:30 PM to about 7 AM.

So, that brings me to these questions:

1. Which of those timers is better ?

2. When you installed them, did you notice a savings in your electric bill , once they were in use?

3 On the electronic timers, how long does the battery usually last ?

[John K Jordan]

...Must be doing that to keep the water up to temperature. ...

I can't answer about a timer. I suspect the savings might not be that great since when the timer cut on the heater would have to run continuously for a long time to reheat a much colder mass of water. Seems like much would depend on the insulation. To see if it would help you might do the math based on your projected schedule of hot water need.

Have you installed or considered installing extra insulation around and especially above the heater? Even HD sells insulation blankets for this. Since the thermostat is turning on the heater every 1/2 hour or so when it cools down, bundling it up in thick insulation might extend that significantly. (It will probably make the room the heater is in a little cooler though!)

Another thing you can do if you haven't is check the thermostat setting and turn the thermostat down if possible. The last time I bought a new heater the default setting was way higher then needed. I have mine set to 120 deg.

JKJ

[Mike Cutler]

Clarence

I've never used one for a storage tank water heater, but I have used them for outdoor water troughs for horses. The one I used was a 24 hour, electric timer. It was powered by the line voltage in, so there were no batteries. It worked for this application
In theory it should work, saving you $$$$, but you will need to insulate the water heater and piping. You could also lower the temperature of the heating elements.
When you're water heater is maintaining temp, it is only cycling one element on and off, if the temp gets to low, both will turn on. I'm fairly certain that if you use a a timer you would get low enough in temp to turn on both elements, when the timer finally allows power to the heater.
I don't know what the actual savings would be to have it cycle on and off one element for a few minutes, versus cycling them both on and off for a longer period of time. You might have to change the wiring strategy in the water heater to have both elements cycle together.

We got rid of our electric water heater years ago and switched back to propane. Heating water with electricity is just to expensive in Connecticut. It was the only way I could figure out how to lower the hit on the bill from the water heater.

[Jim Becker]

You'd have to balance the energy use for bringing the water back up to temperature after it cools considerably (timer off) vs the periodic short term energy use for maintaining the temperature in range. Insulation is a must anyway, so I'd try beefing that up and see if there is a positive effect on energy costs before doing the timer thing. Many years ago, I did have a timer on an electric water heater...it was mechanical. I don't recall at this point if it made any meaningful difference, honestly.

In this house, we use gas-fired tankless water heaters. No energy is expended unless there is an actual need for hot water...and at that point, it's "endless", too.

[Clarence Martinn]

I thought of going the tankless route, but we have very hard water along with some grit and iron in the water. Not sure how a tankless water heater can handle that type of water.

[Jim Becker]

I thought of going the tankless route, but we have very hard water along with some grit and iron in the water. Not sure how a tankless water heater can handle that type of water.

Our water isn't all that different and we've had no issues. Sediment should be filtered out post the pressure tank so that would be moot if you have the filter. There is a maintenance procedure that can and should be done periodically to deal with any chemical effects of the particular water supply.

[Bradley Gray]

I have had a mechanical timer for 25 years. My water heater runs for an hour early in the morning and an hour late afternoon. It has an override if we need more hot water.

An added benefit I just realized - I just replaced my 25 year old water heater last week. I doubt it would have lasted anywhere near this long if it was always on.

I looked at tank-less but my house only has 100 amp service and they are power hogs when they are on.

[Lee Schierer]

When we had the time of day rate meter we only allowed the water heater to run during off peak times. The 45 gallons would last all day. We ran the dishwasher and most showers during off peak times. We no longer have the off peak meter or rate strcture available to us.

We had a 24 hour mechanical timer. I would go with electronic if it offers 7 day program capabilities.

[Nike Nihiser]

I thought of going the tankless route, but we have very hard water along with some grit and iron in the water. Not sure how a tankless water heater can handle that type of water.

Very hard, gritty water is going to be just as bad or nearly so for the electric water heater as it is for the tankless.

[Steve Peterson]

It seems like you would save money just because the heater would always be running at the nighttime rate.

My concern is why does the heater cycle so often? It sounds like a new heater, so it should be well insulated. Are the pipes near the heater insulated?

Some houses have a loop in the pipes to allow the hot water to continuously circulate so there is always hot water near the sinks. Some are passive with one half insulated and the other side uninsulated so it forms a convection loop. This would always be returning water that has cooled off back to the heater. Another mode uses a pump. In either case it seems like a waste of heat with some water savings because you won't need to waste water waiting for hot water. We had the pump style at our old house. I put a remote control on the pump, so we could turn on the pump a few minutes before getting into the shower.

[Mike Cutler]

I looked at tank-less but my house only has 100 amp service and they are power hogs when they are on.

Bradley
Look into natural gas, or propane for a tankless system. An electric tankless would be a huge amp draw.

[Mike Henderson]

Bradley
Look into natural gas, or proper for a tankless system. An electric tankless would be a huge amp draw.

Amen. You sure don't want to do an electric tankless.

But if you have natural gas, a tankless is great. Around here, natural gas is pretty cheap but I did notice a reduction in my bill when I installed a tankless. And as Jim pointed out, when you install a tankless, you need to put a filter on the input line. They make filters specifically for that. You also need to do a yearly maintenance where you pump vinegar or a calcium dissolving product through the heater to remove any calcium buildup in the tubes.

One negative is that if you have a power outage you won't have hot water. But where I am, that's not a problem. I'm a real believer in tankless.

Mike

[Update] Here's a picture of the latest tank to tankless conversion I've done. Note that the water lines are up high on the wall where they would be for a tank, so it took some routing to get the water to the underside of the tankless. Also note the blue water filter on the cold water line. This is a condensing tankless heater so the exhaust is not hot and, therefore, 3 inch schedule 40 PVC can be used for the intake and exhaust. A tankless generally requires a 3/4" gas line. I took the tank out one day and then the plumber and I did the hanging and plumbing the next day. After he finished, I did the venting. It was a full day and I didn't have to do any electrical - there was an outlet close by. It's in a small closet with a door to the outside.
2017-12-10-Tankless.jpg

[Jim Becker]

Mike, I believe that's the same unit that I have two of in our home, although mine has the original manufacturer name on it rather than Rheem. They are great!

[Mike Henderson]

Mike, I believe that's the same unit that I have two of in our home, although mine has the original manufacturer name on it rather than Rheem. They are great!

Who is the original manufacturer, Jim? I thought Rheem made these.

Mike

[Jim Becker]

WaiWela ..........