Another water heater question.

Steve@Advance

Well-known Member
I'm looking to replace my 20 year old electric water heater soon.

I have a household of 3, myself with minimal needs, but a wife and teen daughter that... do girly stuff in the bathroom involving mass quantities of hot water...

I currently have a 50 gallon that works well, or it did till the lower element went out. I'm scared to try to replace it, might start a leak and I'm sure it's full of calcium.

So, my choices are:
Go with a 50 gallon Rheem Marathon, fiberglass tank,lifetime guarantee, uses standard elements and thermostats, $800.00.

Or a 27kw tankless heater. I'v read good things about them but never actually seen one in use. Somehow it's supposed to drastically lower energy consumption, but I can't see how? It costs $500.00.

My concern is the 115 amps it requires to operate. I have a 200a service. If the water heater (115a), electric furnace(63a), dishwasher (10a?), electric range & oven(40?), dryer (30a) plus misc are all on...

As you can see I'm well over the 200a limit. I've read several reviews and no one has complained about tripping the main or dimming the lights or burning the buss bars...

What am I missing here? Is the 115 amps a worse case situation that rarely happens? Are the elements powered up one at a time only as needed? Am I sizing this properly?

Anyone have one of these or have a recommendation?
Thanks!
 
Put a new element in your old one for now, they are cheap! Clean out the calcium and flush it out. Have a new drain valve available, that's the only problem I ever had, destroyed it getting it to open.
 
Check with your electrical supplier, some have programs to put in a Matathon at reduced rates.

I got an 80 gallon Marathon installed for $120 out of my pocket in the early 1990s. Really haven't thought about it, it just works.

Paul
 
I would fix the old one also. The last thing I would do is install a instant water heater if I had people in the house that used excessive amounts of hot water.
 
Sorry but I wouldn't replace and element. Have seen too many people break off bolts and stuff. If you get a little older then the troubles of getting it in and out of the basement and the costs just keep going up. My $.o2
 
Didn't Ask This Old House do a segment on tankless water heaters and said electric one not all that great? I seen them replace a lot with gas tho.
 

With an electric furnace and electric range and 200 amp service you should forget about electrically powered on-demand water heaters. It is completely realistic for the furnace, water heat, and range to all be on at once. You are already perilously close to the limits of your service with just these 3 loads.

If your primary heat is that electric furnace, and if the water heater is located within the heated envelope of the house, the stand-by losses of a storage tank cost you zero in the winter time. (The heat lost from the tank heats the house, which you need to do anyway).
 
The first thing I would do is replace the element. If something breaks or leaks you're not out much for the element and you were going to replace the whole heater anyway. If it works, and it probably will, you just saved a bunch of money.
Whenever I work on a water heater I always have the shop vac handy. Works good for cleaning up spills and leaks before they get too big. If you can't get the drain valve to work, you can unscrew the element (not all the way, just until water starts running out) and suck up the water with the vac. Screw the element in, empty the vac and repeat until empty.
When you get the bottom element out, make a flexible extension for the vac hose and remove the sediment and deposits from the bottom of the tank.
About the tankless heater, don't do it! I added a third bathroom to our house and I was going to replace the 50 gallon water heater with an 80 gallon. Then I thought about my daughters staying in the bathroom until the water heater was empty and I kept the 50. Now they run out of hot water before I run out of money.
 
Hmm. Since you've already decided to trash the old heater, what do you have to lose by changing out the element? You gotta drain it to move it, anyway.

A tankless heater saves money, in theory, because it doesn't need to keep 40 or 50 gallons of water hot all the time. But there are other ways to save cost with an electric heater. See if your power company offers interruptible water heater service; you pay a much cheaper rate in exchange for letting the utility cut your service for a few minutes out of the hour during peak demand. Or, if nobody is home during the day, consider putting the water heater on a timer.

You are wise to be concerned about your 200 amp service being adequate to handle a 27 kW water heater. Just the furnace and water heater alone will have you service nearly tapped out. You're likely to see lights dimming when the water heater kicks in, even if it doesn't trip your main. You could go with a slightly smaller unit; I see Rheem offers two 5 gpm units, one 27 kw and another rated at 18 kw/75 amps. The latter seems more reasonable, but I'd still be concerned. If it was my house, I'd stick with a conventional water heater.
 
I tried the electric tankless route for a few miserable months. It was exciting in the shower going from scalding to freezing and back each time my pump cycled or another faucet in the house was used. I gave that junk away and am now the happy owner of a traditional storage tank water heater. I never noticed any lowering of my electric use either. TDF
 
There is a type of electric water heater that has been out for a a couple of years now.

A Electric Heat Pump water heater. It works similar to a heat pump that is used to heat a house only on a smaller scale.

Next hot water heater I have to buy I will look at one of those heat pump water heaters.

Daughter put one in there house of 4 people and seems to work okay with less power usage than a electric resistant heat water heater.

Check it out.
Heat pump water heater.
 

I assume when you say full of calcium, that you have very hard water. For me that eliminates a tankless heater immediately. It will scale up way faster than your tank. I have replaced many elements in hot water heaters where the water was hard. Just get your self set up with everything you need. If it bolts in get a couple spare bolts. We used to always carry spare elements and spare bolts on the truck, and plan on replacing bad elements when we encountered them. For hard water you should put in a low watt density element. It takes them a lot longer to scale up.
 
Tankless is not going to "drastically" lower anything except maybe the weight of your wallet.
A good well insulated tank-heater uses very little energy when in "stand-by." A tank heater uses the same power and some use less then a tankless when actually heating the water. The main gain to having a tankless is when you need hot water in a remote area and don't need it often.
 
Steve, you can't go tankless unless you have a softner. Lime will build up in the tankless too.

Replacing elements is a PIA. I use my shop vac and a small hose to suck the lime out. The last element was a big challenge to get out. Most of the time getting the element out is much easier.

There are lifetime elements, hi density that will last forever in lime. The last set, I ordered from amazon. They were less than $25 each. Ordering 2 elements meant free shipping. Besides you have a top and bottom element.

I will never go tankless.

What do you have to lose, fix yours.

Harbor freight sells water alarms for around $10. If you are worried about leaks, get an alarm.

I worry about plumbing leaks, because I have a well. My pump is in the basement. I rigged up an alarm with a switch. My alarm will kill the power to the pump. 3 months after installing the alarm, I had a leak, and alarm worked, Thank
GOD.

Go for it.
George
 
If and when anyone replaces the drain valve on a water heater, use a FULL PORT ball valve with a male 3/4" garden hose adapter screwed into it. That way the valve will work when you need it to and it will drain your tank much faster. The hole in the drain valve that comes with a water heater is about the size of a pencil.
 
Where do these experts on electric use come from. If you have a 200 amp service in your home you can run several heaters and your pump and all of your appliances at the same time and not be anywhere near the limit on your electric power. In fact you would not even use half of your available power. Many farms are running on 200 amp service and they do not have any problems even though many use the same service to power their homes.
 
Thanks everyone for your responses! Sure glad I asked before buying something I wouldn't be happy with.

I won't be going tankless, too many negatives.

I can't go gas, it's not available in the neighborhood.

I'm still leaning toward the Rheem Marathon. I've put in 2 for other people, one a year ago, the other last week. So far so good. Paul, good to hear yours has been working for 20+ years, that's what I wanted to hear!

I did hard plumb a 3/4 ball valve for a drain on both, plan to do the same with mine. I do have hard, scaly water and no softener. With the plumbed in valve I can flush the lime out without dragging out the hose, which means I'd probably never do it...

The reason I'm hesitant to change the element in the old heater because no one stocks the Marathon heaters locally. Takes about 2 weeks to get one. Don't want to be forced to buy another steel tank if I twist the fitting out of the old one!

Thanks again everyone!
 
The lime and calcium maybe keeping the 20yr old heater from leaking.
A tankless heater doesn"t work with a standby generator.
If your power is metered via time of use. A timer on the bottom element to heat 3/4 of the tank during the lowest electrical rates will save many bucks.
When ripping around in the utity room anyways. This is the time to considering a water softener. You will wonder why you went without a WS afterwards.
 
Bus bars just how old is your main service. I would think of replacing that before you burn the house down.
I have a marathon water heater it's works great and looks good if it's out in the open.
Walt
 

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