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Q: Installing 2nd Water Heater - Need advice ( Answered 4 out of 5 stars,   2 Comments )
Subject: Installing 2nd Water Heater - Need advice
Category: Family and Home > Home
Asked by: research_help-ga
List Price: $10.00
Posted: 20 Jan 2005 07:05 PST
Expires: 19 Feb 2005 07:05 PST
Question ID: 460388
I am considering adding an additional electric water heater to my
house.  I currently have a 50 gallon electric, but it is not enough
for our current needs.  I would like a few articles including a
schematic or drawing of how they should be installed.  For example, I
am planning on installing them in series, is this recommended? Do you
put the larger one first in the series or second? Are there any things
I should be aware of about trying to install a second water heater?
Subject: Re: Installing 2nd Water Heater - Need advice
Answered By: redhoss-ga on 20 Jan 2005 09:18 PST
Rated:4 out of 5 stars
Hello research_help, I don't know who advised you to install your
proposed second heater in series, but from what I read they gave you
good advise. The only reason to consider parallel installation would
be if you required large quantities of hot water over a short period
of time (such as filling a large tub quickly). I am sure that you are
probably aware that electric water heaters have a much slower recovery
time than gas heaters. Possibly if your 50 gallon electric heater were
gas it might be adequate. However, you probably have an all electric
home. I found only one schematic for installing two water heaters in
series, but it is correct and very clear. I will assume that you are
able to view .pdf files. If you can't, please ask for clarification
and I will explain how.

From what I learned from this article your second heater could be of a
lesser capacity unless you want to get a new heater which is larger
than your 50 gallon and use your existing heater as the secondary
heater. The only other suggestion I have is that you might want to
consider tankless water heaters. There are some advantages not
obtained by the two heaters in series. You don't say how many
bathrooms you have or how your house is arranged. Note that some of
this info has different plans depending on type of house. The greatest
benefit that I see is that you don't have to wait for hot water to be
delivered from a great distance while you shiver in the shower.


 You will never run out of hot water. "You want an hour long shower? No problem!" 
 Electric units can be installed at the point of use. 
 You're not paying energy costs to heat water 24 hours a day. 
 They're easy to install. 
 Our electric units don't require a T&P valve. (No tank!) 
 Installing a tankless water heater will indeed be a bonus to the
environment (why should we choose wastefulness when we're talking
about finite natural resources)?


 They all need a minimum flow rate & pressure to turn on. 
 The faster water flows through them, the lower the temperature rise.
So don't expect to take a shower while the clothes washer is running.
(gas units handle this a little better than electric models)
 Electric units need heavy gauge wire. Example: the 9.5kw must have
8ga wire and a 50amp breaker.
 Gas units need a much larger flue pipe and gas supply than a
conventional water heater.
 At times they can produce very hot water. It's easier to get scalded. 
 Gas units are more complicated than a conventional water heater. 
 With some brands, parts are hard to find (not a negative if you
originally purchase from us, as we like to carry parts for the units
that we sell).

PLUMBING Tankless Water Heater Installation GUIDE

Tankless Water Heater Applications 

 Residential Floor Plan Diagrams
1. Standard One Story Home Options 
2. Standard Two Story Home Options 
3. One Story / Booster for Quicker Response 

I am not selling tankless systems. I only offered this as an
alternative for your consideration. Please let me know by asking for a
clarification if I have left out anything you need to know.

Good luck with your upgrade, Redhoss

Request for Answer Clarification by research_help-ga on 20 Jan 2005 09:41 PST
Thank you, redhoss. You have gathered a lot of information.  I was
wondering if you could include links or excerpts from the articles
where you gathered the information that was pertinent to my question. 
Please note that I am not interested in information about tankless
water heaters.

Clarification of Answer by redhoss-ga on 20 Jan 2005 10:52 PST
I am sorry now that I included the info about tankless heaters. I just
didn't know whether you had considered it. The only useful info I
found related to your series installation is in the .pdf document
found here:

This has a complete diagram as well as a good explanation of parallel
versus series installations. It also discusses sizing and electric
versus gas considerations. If you can't open .pdf documents, you will
need to download this:

Unfortunately this is the only format that this information is
available in. It is the only source I could find with the information
you need. However, if after studying it you still have questions,
please ask for more clarification.

Request for Answer Clarification by research_help-ga on 21 Jan 2005 05:48 PST
Thank you for the clarification. I was able to read the one pdf
document regarding my question.  What I was asking for was additional
sources of information. Please see my original question "I would like
a few articles including a schematic or drawing..." and my request for
clarification "...include links or excerpts from the articles..."
As you can see, I had asked for and was hoping to get more than one
source of information for my question. Please let me know if this is

Clarification of Answer by redhoss-ga on 21 Jan 2005 11:00 PST
Yes sir, I understand that you wanted more than one article and
believe me I tried very hard to find some others. However, every
reference I found was this exact same .pdf document that I gave you. I
agree that normally I would require several pieces of information to
get other opinions about a question that I have. In this case the one
document appears to be the ultimate authority on the subject. I am a
mechanical engineer and when I first read your question I thought that
the best solution would be to connect the two water heaters in
parallel. However, after reading the article I understood that series
is the best with absolutely no doubt. I also know enough about
plumbing to see that the diagram for series connection is the only way
to connect two water heaters. When you have the perfect answer to a
question from a very credible source does a person actually need
research_help-ga rated this answer:4 out of 5 stars
I would have liked an additional source, as requested in the original
question, but the information given was useful.  Thanks

Subject: Re: Installing 2nd Water Heater - Need advice
From: frde-ga on 21 Jan 2005 06:13 PST
In series ?

The mind boggles
Subject: Re: Installing 2nd Water Heater - Need advice
From: hubbie-ga on 26 Jan 2005 15:52 PST

Tankless water heater is a great solution to what you want to accomplish.
You can install it in parallel or series, depending on specific needs. Both
ways are ok. You can find an installation diagram here: <a
Water Heater Diagram</a> offers excellent heaters. My neighbor installed it
to supplement his solar water heater, for when it is not so sunny.

I use it myself to extend my hot water from my tank heater. The greatest
advantange is that I don't have to have 2 huge tanks sitting there, keeping the
water warm all the time. I am so happy with the performance that I plan to
install the Twin Titan configuration withing the next few months, replacing
my tank heater all together.

I hope my post provides you with useful advice. Just add a comment if you need
to ask me something.

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