New Boiler Tankless Hot Water Heater Combo In Connecticut


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Old 05-23-14, 08:00 AM
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New Boiler Tankless Hot Water Heater Combo In Connecticut

I have a 2500 sq ft ranch house in Connecticut. I want to replace my exiting boiler, which also makes my domestic hot water. I'm researching the options for a combo unit for both heat and tankless domestic hot water and I'd appreciate some recommendations. The unit will be installed inside the basement and use natural gas.

One company I've seriously considered is AO Smith. (http://www.aosmith.comOperatingUnits/Detail.aspx?id=138)

They own the AO Smith brand, the Takagi brand, and the State brand. As I understand it they make the same unit under all three brands the only difference being the label. The three units are:


-The Takagi model T-H3
Takagi USA - The tankless water heater pioneers. Experience "Endless Hot Water"

-State Industries is model State 540
http://www.statewaterheaters.com/lit...40-340-540.pdf

-AO Smith model 540
Tankless Water Heater Condensing Ultra-Low NOx Outdoor 199,000 BTU Natural Gas | A. O. Smith Water Heaters

These units all started as a hot water heater and then they added the home heating ability. The only reason I can see to choose one of the above over the other is depending on the installer who may prefer to buy from one company over the other. I believe these models are all the correct size for my house.

***

I've spoken to four plumber installers in my area and they all like the Triangle Tube Challenger Combination Boiler. This unit started as a Condensing Boiler and they then added the hot water.
Challenger Combination Boiler | TriangleTube


I think any of these units would work. It looks like the Triangle Tub equipment is a little more expensive to buy. I spoke to technical support at both companies and both were very knowledgeable and helpful.

Both are condensing units. The hot gases produced in the combustion process is water vapor (steam), which arises from burning the hydrogen content of the fuel. A condensing boiler extracts additional heat from the waste gases by condensing this water vapor to liquid water, thus recovering its latent heat of vaporization. The condensate produced is acidic so the water is generally run through a neutralizer and then the water is pumped out the sewer drain pipe (or it can be ejected outside, but sometimes this can freeze). The condensate drain needs to have a trap.


What's your experience with the above combo units and what other combo units would you suggest checking out.

Thanks.

Steve
 
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Old 05-23-14, 12:47 PM
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Before you do ANYTHING get a manual-J, a load calculation done. 199k for a 2500 foot home is huge. Ideally you'll size your boiler to the heat loss.

I looked at combo units and decided to go with a Munchkin condensing boiler and an indirect.
 
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Old 05-23-14, 01:46 PM
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Why are you needing to replace your existing boiler?
 
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Old 05-24-14, 08:32 AM
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199k for a 2500 foot home is huge. Ideally you'll size your boiler to the heat loss.
My 2-story, 1950s house has 3600 sq ft. The calculated, design heat loss, using the Slant/Fin program, is 106,000 Btu/hr. That works out to 29.4 Btu/hr/sq ft. I tend to agree with Dan that your are probably considering massively oversized boilers - likely by more than a factor of two.

Most boiler salesmen won't bother to run a heat-loss calculation, even if they know how, for free on speculation that you will buy a boiler from them and not share their results with competitors.
 
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Old 05-24-14, 08:39 AM
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I'd like to emphasize what everyone else has said about properly sizing the equipment. It is VERY COMMON to have a boiler that is massively oversized due to ignorance and sloth on the part of the SALESMAN

And I also emphasize SALESMAN ... they simply DO NOT CARE and most often do not KNOW that the boiler is two or three times as big as it needs to be as long as you sign the bottom line. Once you do that, their job is done, and you are the one that has to live with an oversized boiler for the next 20 years or so. $$$

It is YOUR responsibility to be sure that you get what you need.
 
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Old 05-24-14, 11:04 AM
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I appreciate all the comments about oversizing the boiler and the need to do a heat loss calculation.

Please remember that I am in a cold climate being in Connecticut and also remember that I am using this boiler to make heat and domestic hot water. Could either of these factors account for the need for a larger unit?

Steve
 
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Old 05-24-14, 01:30 PM
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Could either of these factors account for the need for a larger unit?
No, not really... BUT... the 'tankless water heaters' that double as space heating appliances DO have a higher BTU rating in order to provide that 'instant hot water' feature.

Do the heat loss estimate yourself so you have an idea of what your home needs for heating and go from there.

Example: My 2000 sq ft home heat loss is about 55K BTUH. I don't use the boiler for domestic hot water though.
 
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Old 05-27-14, 06:21 PM
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I would do a boiler with an indirect waster heater for efficiency. It is cheaper to heat still water over moving water. Let's talk about heating water you don't need to use right now. You will see advertisements about the cost of making hot water you don't use now. What do they compare themselves to? I have seen tankless compared to electric, gas and oil fired water heaters. Two differences, less insulation than an indirect and possibly connected to a chimney. Both is a good argument. But the indirect, which i never see tankless heater's compared to, the indirect is insulated to less than 1 degree per hour standby loss and no chimney losses. I feel it is a better choice to go with a boiler and indirect.
 
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Old 05-27-14, 07:33 PM
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Additionally what was stated already....


IMO, and from the units I have installed, you may not be happy with the hot water being heated with a tank-less unit.. There is the sandwich effect you get where you get cold slugs of water. You need to wait longer for hot water because the unit has to activate/fire when water is drawn. ( To fix these issues a buffer tank is installed as well as a recirc line with pump.. Additional costs)

Also average water temp is say 54F coming out of the ground here in NJ. (same for you?)If you look at the specs the GPM they advertise is for 70F water coming into the unit. So right there the GPM gets reduced.

You need to look at the temp rise the unit can produce at what degree water....I have seen homes with a 199k btu unit get no more then 3 gpm.

With that said how many bathrooms in the home?

Next onto the boiler... As was stated why are you replacing, and whats there now? Are you replacing to save fuel costs? Because these units are expensive your payback may take a long, long time..

You can simply disconnect the tankless coil and install a conventional heater and save money over the cost of a new system. You need to do the calculation but you may be in the 60-70k btu range for boiler sizing.

Last what type of heat emitters in the home? Cast iron rads? Copper finned baseboard? How may zones?

How many ft of element only if copper finned BB is on each zone? ( This will tell you if your a good candidate for a mod con boiler that will run at lower temps...

IMO I would stick to a cast iron boiler such as a slant fin or burnham if indeed you really need to change your boiler..

I like the series 2 burnhams

Series 2 Gas Fired Cast Iron Water Boiler | U.S. Boiler Company

Slant fin sentry( Very good controls IMO)

Sentry

And couple any of them with a supor stor contender indirect..( The ssc 35 only requires a 53k btu boiler at a minimum)

Superstor Contender Indirect Water Heater

Last if you really want a condensing boiler my choice would be the peerless purefire.. ( Coupled with the indirect) I like the ease of installation. SS burner and on board neutralizer...(hard to get these though)

Peerless® PUREFIRE®
 
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Old 05-28-14, 06:18 AM
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Thank you for all the great input.

Currently I have a Weil-McLain oil fired boiler with a Riello buner, which also makes domestic hot water. It is around 18 years old. I want to replace it so I can convert to a natural gas fired unit.

I have spoken to several installers who all advise against converting the existing boiler to run on gas, even though it is possible. They all say the converted boiler will be very inefficient.

I have two friends (New York and Colorado) that have tankless hot water heaters and are both very happy. In Colorado the tankless unit also provides radiant floor heat throughout a 2000 sq ft house.

My house is heated with copper baseboards with one zone and the house is around 1400 sq ft on one floor.

About 150 ft of copper finned baseboard.

Steve
 
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Old 05-28-14, 06:40 AM
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I have two friends (New York and Colorado) that have tankless hot water heaters and are both very happy.

Most people say that because they need to justify the 5K plus price tag of the install. I hear it all the time... After the thrill of the tankless unit wears off, and the units become 5 or more years old, I end up removing them and installing back to traditional heaters..

This is after I tell them what the repair will be on these complicated units when called to trouble shoot.

Basically you can install 5 regular water heaters for the price of a tank-less unit initial install at current price and labor costs. If each regular heater lasted 10 years, then that's 50 years..

Do the math. Its a no brainer IMO.

My house is heated with copper baseboards with one zone and the house is around 1400 sq ft on one floor.

About 150 ft of copper finned baseboard.
Two floors?
How many ft on each floor?

And this is not the covers of the basboard. I am talking element only in ft... You have to look in the covers and measure..
 
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Old 05-28-14, 07:38 AM
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I have a 2500 sq ft ranch house in Connecticut.
copper baseboards with one zone and the house is around 1400 sq ft on one floor.
Huh???









Is the gas meter run to the home yet?

Yes IMO conversions are not that great but you will save oodles of $$ switching to gas...


My honest opinion as example...

Supor stor ssc 35 $660...

Superstor Contender, SSC-35, Glass Lined Indirect Water Heater

Burnham with DOE of 52 K. ( This is why you need to do a heat loss) Can probably find free shipping... $1900

P203-EI-NG - Burnham P203-EI-NG - P203 45,000 BTU Output, Electronic Ignition Cast Iron Boiler (Nat Gas)

So lets say $2600.

Now find an installer. Get some estimates. I would say two days work, two guys. With near boiler piping, labor, gas line run and materials should be in the 3k range IMO.

$5500 or so and your done... With a more reliable unit with less moving parts.


Have you recieved quotes for these combis installed?

And dont get me wrong. Tank-less units do have their place... Space saving, and large family's with children of school age that shower one after another.
 
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Old 05-28-14, 07:40 AM
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Use the slant fin heat loss calc found here...

http://www.doityourself.com/forum/bo...lculators.html
 
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Old 05-28-14, 07:46 AM
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Mike,

Gas meter is not yet installed but gas company is to do it.

Sorry about the confusion of the size of the house. The house is currently 1400 sq ft, but I have plans to at some point increase it to 2500 sq ft.

Thanks for all your input!

Steve
 
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Old 05-28-14, 08:23 AM
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Do the heat loss and post back..

And tell us the if you really have 150 ft of element on one zone...

Also if you size to your reno @ 2500 sq ft the boiler will be oversized. If you size to your current sq ft then that boiler will be two small when you do the reno.

It may be beneficial to install the smaller boiler and add another after the reno is completed. having them cascade.

Or a mod con boiler may be of some benefit because it down fires. But after the reno it will fire higher and act like any other boiler and eff will be decreased.

But if you do have 150 ft of BB, thats 82k btu output at 180f boiler water temp.. Thats huge for a 14 k sq ft home. You only need about 35K BTU from my rough estimate

So on the coldest day of the year a mod con should be able to heat the home and stay in condensing mode for what you have. 150 ft bb x 250 = 37500 btu..

( You see you only need 130 f boiler water temp to output 37500 btu out of 150 ft base board... See chart below)


I hope i am not confusing you with all this info... You can step back and take a breather...LOL.. If I am giving you too much info just let me know....


 
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Old 05-28-14, 05:19 PM
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New Boiler Tankless Hot Water Heater Combo In Connecticut Read more

Last if you really want a condensing boiler my choice would be the peerless purefire.. ( Coupled with the indirect) I like the ease of installation. SS burner and on board neutralizer...(hard to get these though)

Peerless® PUREFIRE®

Read more: http://www.doityourself.com/forum/bo...#ixzz333jB15SR
Mike,

Why do you say it is hard to get the Peerless® PUREFIRE®? Is it hard to find a distributor, installer, service, and parts?

Steve
 
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Old 05-28-14, 06:07 PM
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You used to need to be in the industry to get them... Hmmm. I guess pex supply has them now...

Peerless Boilers - Peerless Purefire Boilers - Purefire Boilers - Peerless Gas Boilers - SupplyHouse.com
 
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Old 06-08-14, 01:34 PM
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Mike,

I like the series 2 burnhams

Series 2 Gas Fired Cast Iron Water Boiler | U.S. Boiler Company

Slant fin sentry( Very good controls IMO)

Sentry

And couple any of them with a supor stor contender indirect..( The ssc 35 only requires a 53k btu boiler at a minimum)

Superstor Contender Indirect Water Heater

Last if you really want a condensing boiler my choice would be the peerless purefire.. ( Coupled with the indirect) I like the ease of installation. SS burner and on board neutralizer...(hard to get these though)

Peerless® PUREFIRE®

Read more: http://www.doityourself.com/forum/bo...#ixzz34570PcaF
I have been looking at the above boilers and was looking closely at the Peerless PUREFIRE as I like the efficiency of condensing boiler, but I notice that it is NOT cast iron and instead they use stainless steel. Does this shorten the life? I thought the advantage of the conventional boilers over the on-demand wall hanging units was the cast iron construction.

Steve
 
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Old 06-08-14, 02:38 PM
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Read here... This should give you the info your asking better then I can explain it...

Condensing boiler - Wikipedia, the free encyclopedia
 
 

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