Dual Electric Hot Water Heaters? - Plumbing - DIY Home Improvement | DIYChatroom
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Plumbing

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Like Tree2Likes
  • 1 Post By hkstroud
  • 1 Post By DR P
Reply
 
Thread Tools Search this Thread
Display Modes
Old 12-16-2017, 08:10 PM   #1
Member
 
fred93's Avatar
 
Join Date: Nov 2017
Posts: 42
Rewards Points: 84
Default

Dual electric hot water heaters?


My house has a 50 gallon electric hot water heater. It is over ten years old and I was thinking about replacing it before it stops working. I figured that I would buy a bigger unit because we seem to run out of hot water sometimes-even though there is only two of us in the house. The wife has a tendency to take long, very hot showers most of the time and if it is winter time the water coming into the house is much colder therefore the recovery time is longer.

When I started to look around for a bigger unit I was told that 50 gallon is the biggest I can buy for a home unit. If that is true I was thinkinking about installing TWO 50 gallon units.

Any thoughts on this?

Also--If I do install TWO units is there any preference on temp settings for the TWO units?
fred93 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 12-16-2017, 08:25 PM   #2
Usually Confused
 
lenaitch's Avatar
 
Join Date: Feb 2014
Location: Central Ontario, Canada
Posts: 6,240
Rewards Points: 2,040
Default

Re: Dual electric hot water heaters?


I have a hard time believing 2 people, even taking long showers, can outrun a properly functioning 50gal heater. When was the last time you flushed it out using the bottom drain valve? Depending on your water, there could be a lot of sediment. Also, do you know both elements are working? I'll leave to others to jump in and advise how to test them.

Maintaining 100gal of hot water will have a significant impact on your electrical usage.

BTW, the incoming cold supply won't vary more than a degree or two over the seasons; certainly not enough to affect the operation of the heater.
__________________
_________________________________________

Bydand
lenaitch is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 12-17-2017, 12:55 AM   #3
Member
 
hkstroud's Avatar
 
Join Date: Mar 2011
Location: Virginia
Posts: 3,356
Rewards Points: 6,694
Default

Re: Dual electric hot water heaters?


Quote:
It is over ten years old and I was thinking about replacing it before it stops working.
Age is not a reason to replace a water heater. In my opinion, leaking is the only reason to replace a water heater.

There are only 4 working parts to an electric water heater. There is the upper thermostat and heating element and there is the lower thermostat and heating element.
Determining if one of those parts is not working is relatively simple. When the upper thermostat calls for heat it turns on the upper heating element. When the upper thermostat is satisfied, it switches control to the lower thermostat and the lower thermostat turns on the lower heating element. The upper heating element heats water in the upper part of the tank. the lower heating element heats water in the lower part of the tank

You know when the upper thermostat or heating element fails because you simply don't have any hot water. Remember the lower heating element doesn't come on until the upper heating element is done heating the upper part of the tank.

Obviously your upper thermostat and heating element work because you have some hot water.

Checking thermostats and heating elements is relatively simple with a volt meter. Replacing heating elements is also simple with a water heater element socket. Of course you must drain the tank first.

To drain the water heater first turn electric breakers off. Connect a hose to the drain valve and run it to a sink or drain lower than the water heater. Turn off the cold water input valve or the water heater, open a hot water faucet somewhere and open the drain valve. If you don't have a drain lower than the water heater, run the hose to the sink and drain as much water as you can. Then drain the remainder into buckets.

Remove the lower heating element with your water heater element socket. Heating elements come is 3500, 4500 watts. There is even a 5500 watt element. The most common size used is 4500 watts. You really can use either size. The higher the wattage the faster it heats the water.

Make sure that the replacement element is not longer that the original.
I don't remember exactly but the cost of an element is about $20.

If you have any difficulty, it will probably be draining the tank. Don't forget to open the hot water side of a faucet somewhere. You must let air into the tank for the water to drain out.

P.S.
Don't forget to refill the tank before turning the breakers back on.
R2D2 likes this.
__________________
Harold,
The Left Handed Widget Maker

Last edited by hkstroud; 12-17-2017 at 01:17 AM.
hkstroud is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 12-17-2017, 03:27 AM   #4
Newbie
 
Join Date: Dec 2017
Location: Palm Coast, FL
Posts: 20
Rewards Points: 40
Default

Re: Dual electric hot water heaters?


How about a tankless hot water heater?

I see that you said you old unit was electric and I do not believe the electric version of the tankless units are very efficient but the gas ones are. If you do not have natural gas to your home, you could go with propane. We put one (propane) in about 5 years ago and have never regretted it. Constant hot water, you never run out
R2D2 is offline   Reply With Quote
Old 12-17-2017, 07:34 AM   #5
Guapo
 
Join Date: Dec 2017
Posts: 5,940
Rewards Points: 11,950
Default

Re: Dual electric hot water heaters?


The tankless might be a good idea as long as you can switch back to the tank with the turn of a few valves. That way if the tankless fails, you have an alternative.
Guap0_ is offline   Reply With Quote
Old 12-17-2017, 09:22 AM   #6
Peace be with you
 
DR P's Avatar
 
Join Date: Dec 2017
Location: in hills of Caroline USA
Posts: 933
Rewards Points: 1,860
Default

Re: Dual electric hot water heaters?


B 4 doing anything else U probably should measure the potential flow rate of all your shower head(s) involved...Any body sprays or multiple use valve capability?

Set proper showering temperature, & then immediately capture all that flow into a 5 gallon bucket while timing with stopwatch app until full; convert the time measured into gpm (i.e. - dual shower heads in use & 5 gallon bucket full in 1 minute = 5gpm).

most 50 gallon tanks first hour rating (fhr) is 67 gph so round up to 70 gallons divided by 5 equals 12 minutes showering time... if showering flow rate is 2.5gpm, then total shower time capable is 24 minutes tops... properly adjusted 50 gallon tank in winter shouldn't produce more than 20-25 minutes showering time in first hour... If more time is desired you will need to install flow restricting devices to gain more time

BTW if your water is municipally supplied and stored in water tank towers, the differences of winter time cold water vs summer time temp is as great as 40+`F... this delta T can rob your tank's fhr 2 fold; since the cold flow mixes with hot water thereby tempering the tank while forcing out hot water... also at showering valve the hot again is tempered especially if a scald guard valve id installed..

These reasons r why most all water heater tank literature (electric and gas) recommend a different summer and winter thermostat setting... only real choice to attempt to get same amount of hot water from same size tank in winter time is by turning up temperature setting... Be sure to readjust once warmer temps arrives or you will be wasting more energy by over heating water and then greatly tempering down at shower control...

WARNING - Any settings above 125`F can cause scalding and is done solely at home owners risk. Never adjust someone else's tank less U R liable. If any children or handicap are involved at your residence, please understand exceeding this 125`F limit is dangerous and possibly even deadly.
A setting of 140`f or greater will cause serious burns in 3 seconds...or Less and not worth the liability/risk. Any & all setting needs to be measured and verified with proper thermometer equipment. Never assume thermostat is correct - rarely is...


Peace
Bud9051 likes this.
DR P is offline   Reply With Quote
Old 12-17-2017, 09:59 AM   #7
Member
 
Join Date: Jan 2014
Location: Connecticut
Posts: 1,365
Rewards Points: 127
Default

Re: Dual electric hot water heaters?


Tankless electrics are 100percent efficient or very close to. The problem with tankless electrics is the require a lot of electric power. They require 100 to 160 AMPs at 240 volts and would require upgrading your entry service to 300 AMP or more. At the 19 cents per kWh that I pay for power, I could never justify the cost. Most tankless water heaters require professional annual maintenance and perhaps more often depending on your water quality. You can buy an electric water larger than 50 gallons but has to be on of the self contained heat pump models and most likely not a your local big box. For most of those you need at least 7foot ceiling and perhaps more in the install location and you have to have free air flow, like a basement or garage in an area that doesn’t freeze.
jimn01 is offline   Reply With Quote
Old 12-17-2017, 12:12 PM   #8
Member
 
Join Date: Nov 2015
Location: Maine
Posts: 10,080
Rewards Points: 2,788
Default

Re: Dual electric hot water heaters?


Dr P covered my thinking pretty well, address the volume of hot water needed.
1. I installed low flow shower heads and my two daughters and wife got by just fine in their extra long showers, @ half the water volume.
2. Cheat on the hot water temperature and kick it up to something higher. If scolding is a concern install a mixing valve after the water heater and select your household temperature. Be sure the mixing valve is rated for potable water. I do not know what codes would approve so check.

With a mixing valve right after the water heater your 50 gallons would become 60 or more (just a guess). Add in the low flow shower head and the combination would probably double your available hot water without the added expense of a second unit. If your current water heater in inside your heated living space then the small amount of added heat loss due to the higher setting at least contributes to the heating. Summer ac it would be a penalty, but still small.

Bud
Bud9051 is offline   Reply With Quote
Old 12-17-2017, 02:09 PM   #9
Member
 
fred93's Avatar
 
Join Date: Nov 2017
Posts: 42
Rewards Points: 84
Default

Re: Dual electric hot water heaters?


WOW--Lots of replies--thank you, that's great It may take awhile to get back to each one of you. But as soon as I can I will reply.

Thanks again
fred93 is offline   Reply With Quote
Old 12-17-2017, 06:08 PM   #10
Peace be with you
 
DR P's Avatar
 
Join Date: Dec 2017
Location: in hills of Caroline USA
Posts: 933
Rewards Points: 1,860
Default

Re: Dual electric hot water heaters?


I do not believe u would need 100 gallons of stored hot water...
I recommend 2 - 40 gallon tanks in series but if you truly want 50s I cant stop you other than to state it could almost double (100%) your water heating costs vs two 40s which would only be a 25% increase in water heating costs...if u follow the parameters below.

Since 80 gallon tanks are no longer available - 80 gallons can most efficiently b accomplished by installing 2 - 40 gallon tanks in series but this will also require an extra (4) 120v slots in your current electric panel or installing a subpanel...

U should use the 1st tank as a preheater {by setting both those thermostats @90`F} for 2nd tank, splitting delta T duties & saving even more energy usage by accomplishing at least an 80 gallon hot water footprint {due to 1st hr rating} with only 60 gallons energy usage... or only a 25% increase of your current water heating costs.

do not set both tanks at 120`F since the key to this configuration is n the ability of both tanks energizing independently an element simultaneously{with separate circuits}... btw if both tanks r set @ 120`F - 2nd tank will not truly share heating duties thereby causing 1st tank n series 2 electrically work much harder & also negating 60 vs 80 gallon energy footprint... jacking your usage up by another 25% to 50% increase... good luck

Peace
DR P is offline   Reply With Quote
Sponsored Links
Advertisement
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Can't drain electric water heater dubina Plumbing 35 08-02-2017 08:07 PM
New Water Heaters - "Sometimes" Barely Warm Water PolishPete Plumbing 7 06-13-2014 05:03 AM
Installing an electric water heater in series with boiler paul01420 Plumbing 10 04-20-2013 08:48 PM
Electric vs Oil hot water gbook2 HVAC 20 09-04-2012 12:09 PM
dual water heaters: parallel or series?? broox Plumbing 33 12-19-2010 09:13 PM




Top of Page | View New Posts