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Condensing Water Heaters

peter_19 Member Posts: 10
So I think I am going to use a condensing water heater as the heat source for my DHW and my RFH (not an open system... I will use a HX to transfer heat from the DHW system to the closed RFH system). I am wondering what folks here would recommend for a condensing water heater? Polaris seems to have quality issues. Phoenix is the new version of Voyager which apparently had quality issues as well. Anyone know of a condensing water heater with a good reliability history?


  • KennyG
    KennyG Member Posts: 10
    Condensing water heater

    The Bradford White E Force is a reliable unit. I have one in service for a 7000 square ft house providing radiant floor heat and domestic hot water with an indirect water heater.
    Over two years running and not one service call.
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,314
    maybe I think back wards

    WOuld it not be more cost effective and efficent to use a condensing boiler and an indirect water heater than the other way around? I am not sure why folks like using a water heater for a heat source when the cost of a heat exchanger is factored in with the cost of a condensing water heater. What am I missing?
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • Rich Kontny_3
    Rich Kontny_3 Member Posts: 562
    What we are missing

    We (Americans) are missing a uniform mandated energy policy.The federal Dept. of Energy has done very little if anything to promote true conservation!

    All of us as contractors have installed systems that if not in-efficient are overkill and wasteful. Some day soon as the finite fossil fuel sources decline we will be hit smack dab in the face with this. Even GW realizes we are addicted to oil and over consume, yet he has done little if anything to mandate the highest technology and equipment available.

    What you see happening to the auto industry will filter down to heating fuels etc. The problem is the fact we had mandated minimum mileage standards in the 80s that were voided in favor of profit for special interest groups.

    If you truly are a follower of this web-site and read related links etc you will see the wiser contributors mentioning this. European techniques and codes,solar,geo-thermal etc.

    Leadership is he key and without getting overly political we lack it in this area (along with other issues)

    The ironic part of all of this is the fact that improved equipment is win win but some don't get it.Call me old fashioned or just plain old but when I see a post or picture of a snowmelt system I cringe. Unless it is hooked up to solar or some sort of waste heat they should be universally banned nation wide if fossil fuels are the fuel source. Gas firplaces should not be allowed!

    We over consume and waste like no other country on the planet that has an educated populace. Why ? because we use the stock market as the barometer of our nations health instead of a quality of life measurement.

    Struck a nerve Charlie and I had to vent!
  • MIke_Jonas
    MIke_Jonas Member Posts: 209
    Speak for yourself, Rich

    I, as a contractor, have NEVER installed a system that was inefficient. I have never installed a system that was overkill. I have never installed a system that was wasteful. I've seen plenty of them, fixed them all when homeowner allowed me to.

    Cringe at snowmelt? That's your prerogative. Just because you don't agree with them, doesn't mean the guy down the street is not going to have one installed. That's my business. It's also my business to do the best job I can for what my customer wants.

    The OP came here with an honest question, looking for advice from professionals. If you don't agree with it, that's fine, but I think your off topic political rant should have had it's own thread.

    Contractors' who install inefficient, wasteful, overkill systems?? You admit to doing this, just don't make a general statement that all contractors' do business the same as you.
  • peter_19
    peter_19 Member Posts: 10

    Well, maybe it is backwards, but why is one way better than another? You've got a burner, a tank, a pump and a HX. Why would there be any advantage to having the burner on the radiant side as opposed to the DHW side?

    If I have a 95% efficient water heater (say a Phoenix) and I add about $500 for a HX and associated parts, I get what I need for about the same cost as a mod/con + indirect tank, and I get better DHW service, and I don't have to worry about short cycling my boiler when I have light loads on the radiant side. Which one is more "cost effective and efficient"?

    If I am willing to give up some efficiency, I can go with a Takagi TK3 and a storage tank for a couple thousand dollars less cost. I'm not sure the increased efficiency of a condensing unit is worth that much money, even over a 15 year span.

    But, I'm not an expert... maybe I am missing something. Probably I am. Can someone tell me where I am making my mistake?

  • Derheatmeister
    Derheatmeister Member Posts: 1,514
    Mandated Emission test

    Rich ,I started a topic about this once: Why do we mandate emission control on automobiles and not on heat Generating? (Like in Europa)

    And got a earful about our rights as Americans..
    Why does that have anything to do with this?

    BUT.. Snow melts do (if installed and controlled properly) have there place in our society i.e. emergency helipads..
  • hot_rod
    hot_rod Member Posts: 21,841
    With a tank style heat source

    you have the burner and HX surrounded by water, great heat exchange. Also you run the tank at the desired DHW temperature, 130F for example. As long as them radiant is designed to run below that temperature a close approch HX will supply the radiant.

    With a separate boiler and indirect the boiler kicks up to 180F to recover the DHW. Not quite as efficient and a bit more loss via piping, pumping, etc.

    From my experience the tank capacity (tank with HX for radiant) really does cut down on short cycling IF you have many micro load zones.

    As for dependability between a mod con boiler or a tank style condensor... Jury is still out on that. I have seen TOO many mod cons HX failure in less than 5 years. It's pretty obvious manufacturers are still trying to determine the best design and material. Aluminum block? Stainless coil? And now a cast iron pin style condensing boiler?

    10 -15 years out of a heating appliance may be about right. By then newer and better design and equipment will no doubt exist.

    These days the DHW load trumps the heat load in many cases. If the particular job required a dump load maybe the tank WH with HX suits that job better. You should really put a number to your DHW expectation, just as you do a heat load calc for the space.

    Nothing wrong with conserving DHW, by the way. 20 gallons per day per person is a huge and probably excessive number. When I hauled water, by 5 gallon buckets to my cabin I could get by with 5 gallons a day!

    The Polaris or Phoenix with HX strapped on makes for a tidy small footprint installation. Some jobs require that.

    I don't feel one has a huge advantage over the other, which is why I offer so many options.

    Dependability issues with indirect or fired tanks seems to have more to do with the water conditions they see. In some areas stainless out lasts enamaled steel, and vice versa. You may have noticed manufacturers starting to offer both types of tanks. Doesn't Burnham now offer a stone lined indirect? Hmmmm

    Build the heating system to the customer and application. It's nice to have this many choices. it wasn't always that way :)


    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Glenn Sossin_2
    Glenn Sossin_2 Member Posts: 592
    Question of Value

    Realistically, how much more are you going to save in operating costs over the conventional wall hung heater? An extra 3-5% on efficiency? What does that translate to in dollars? Suppose a family spent $600 per year on hot water usage. They install a condensing water heater and save an extra 5% - thats $30. Wheres the payback?

    How much more does the unit cost? Now you also have a more sophisticated product - and, you need to treat the condensate. Add a condensate pump and treatment device. What about potential added maintenance costs - i.e. cleaning the exchanger? I don't see the value.

    I agree with Charlie - if possible consider a condensing boiler with reset for space heating with an exchanger - now there is some potential to save hundreds of dollars - not a $30 bill each year(before maintenance :) See new Triangle Tube boiler attachment.

    As far as mandated energy policy - I say keep the goverment out of it. They haven't done anything well that I know of except for NASA. They just keep taking more of our money in taxes each year to hire more bureaucrats that like to talk and push paper. Fuel costs in the market place will force consumers to make more intelligent decisions. Let the free markets prevail.

    My $.02

  • Larry Weingarten
    Larry Weingarten Member Posts: 3,230
    In the original post...

    ...suspicion was cast about the Phoenix heater. It's an interesting beast to me and I'm wondering if there is experience out there that supports the suspicion. I've been thinking it would be particularly nice in the "Solar" version. Should I hold off? Is this a Wetstock question?

    Yours, Larry
  • Charlie from wmass
    Charlie from wmass Member Posts: 4,314
    wow did not think I was going to spark this much reaction.

    I was not saying to use an 80% a.f.u.e. dry base gas boiler with a standing pilot. I was thinking of a load proportional boiler with an out door reset. As for snow melt the lack of use of removal equipment like a 1940's dump truck with a plow and tons of salt up hill from a lake or other sensitive area can justify their use. I would prefer a solar or waste heat source but big pictures need to be veiwed here. I am thinking of the carbon foot print involved here. I am assuming that the boiler and a stainless steel indirect heater of proper size with have a much longer service life than a water heater as a hydronic heat source. As far as American v.s. europeanv.s. the world I have to say my father started his trade in Scotland and I was taught my trade from him. European is not the answer to all questions but niether is American either. We as quality installers need to sift through the propoganda of the manufacturers and the Green movement and the oil industry and all the rest to do the best we can with all our resources. I am sticking with boilers for heat until I am shown other wise. I have put in in efficent systems as some people can not afford the moist efficent I can do. But I still like the heat from a Steam job done well.
    Cost is what you spend , value is what you get.

    cell # 413-841-6726
  • bob eck
    bob eck Member Posts: 930

    I would look at using the triangle tube prestige solo with their phase III stainless steel indirect water heater or their new prestige excellence 95% AFUE boiler and ss indirect 3 GPM / 180 GPH all in one unit. please consider using a storage tank to raise cold water temp before it goes into the indirect water heater.
  • peter_19
    peter_19 Member Posts: 10

    Thanks for the on-topic response! I can't seem to find much info on the BW E-Force (I tried the BW website, but couldn't find it on there)? Could you point me in the right direction?
  • tim smith
    tim smith Member Posts: 2,738
    Re: prestige excelence etc

    Both one of my employees and I are going to install the excellence at our houses. I feel it is a good green device. We have had nothing but raves on the Prestige boiler. Serviced the 1st one we installed 3 yrs ago for the 1st time just last week. In great condition, a little deposits on the top tube sheet and in tubes and bottom of collector but not too much. I myself do not like the condensing water heaters, they do not put as much engineering or thought into their design because of being a commodity. But due to cost, they can be effective for some. I usually like to use a Prestige & superstore tank for my jobs and I get much better flow rates for multiple ( many times larger flow than desired) fixtures. Good luck, Tim
  • Rich Kontny_3
    Rich Kontny_3 Member Posts: 562
    Speak for myself?


    I am speaking for not only consrvative minded people but from several other angles. I am a 40 year veteran of the pipe wars and have lived through the wars that led to fuel shortages in the 70's early eighties and the pending shortages due to our current Mideast and world policies.

    Compared to prior administrations Bush has had little or no energy conservation policy other than to let the market determine price. The same approach has been used since the late eighties regarding healthcare and perhaps that will give you a more glaring inflation number.

    Factor in this and maybe (just maybe) you will see where I am coming from and where Derheatmeister can contribute.The Germans and other European nations after WW2 had to rebuild practically a whole continent with limited resources. They did so as Germans often do with top shelf engineering and also a process called planning for the future.Planning for the future is not America's greatest talent as it concentrates on immediate return on investment(our stock market).

    Japan was in the same boat also and had to rebuild there country from ruins back into the economic powerhouse it is today.Remember now and you might want to look this up, two programs (the Allies,mostly America) used to help both Germany and Japan rebuild. I believe it was the Marshall plan in Europe and the Monroe Doctrine in Japan.

    Instead of using their resources on war, they now could concentrate on new infrastructure and rebuilding. They did this and continue to do this in a mandated and well enforced manner. Chimney sweeps yearly inspections,extremely high efficient heat equipment, building envelopes etc.In other words Spicoli they have their entire act together from design to install,maintenance,inspection and forced upgrades.

    This indeed would be a hard sell here because we tend to consume like there is no tomorrow. If you don't believe this, "denial" is not a river in Egypt.So have you ever installed an inefficient heat source based on world standards? I bet you have, you just have not looked at the overall picture!

    Post or e-mail me some of your installs to check out overall for better design, from not only a heatsource standpoint but from an applications standpoint.If you would like, send me your credentials and I in turn will send you mine!

    Now young man (compared to me)I want you to factor in something you may not be able to appreciate.You almost have to come from a military family or have someone close to you in the military.

    Last summer our insurance agent's son (they are close friends) lost his son Matthew in Ramadi,Iraq. Matthew age 20 was the victim of buried exposive device.We of course went to the funeral as not only friends but because our son is Marine (they are for life ) and is now an Army Reserve Drill Instructor.

    You probaly caught me at a bad time here because just yesterday we attended the funeral for even a closer friend's son "James Ehrlich" who was a Navy Seaman that volunteeered to go on the ground in Iraq. James was injured while training at Fort Lewis on Dec 15, 2007 and laid in a coma until two weeks ago when he was taken off of life support. James died early morning April, 2 2008.
    Twenty minutes after his 25th birthday.

    James leaves behind his young wife and 2 year old son Joseph.How does this tie in to this thread and my response? We are fighting for our national interests in the Mideast, the single largest interest is oil! Go back to the denial statement above and you should be able to connect the dots!!!

    Any othor questions?

    Rich K.
  • Rich Kontny_3
    Rich Kontny_3 Member Posts: 562

    You are one of the wiser ones I was refering to and even though you met reluctance here does not mean you were not right. We (Americans) always seem to put $$$$ in front of common sense and what is right in the long term.

    We Americans need the input from contributors like you because you know that there are better ways to improve overall quality of life.

    I also have no problem with emergency or defense type snowmelt systems. Stop at a Starbucks sometime in the summer and see their gas fired fireplace on for ambiance. This will result in an e-mail to there new CEO as they have claims to being a green leader. I will call them on that one.

    Always enjoy your posts Heatmeister please share your knowledge and experience from Europe. Dan Holohan,Hot Rod Rohr and others who have traveled to Europe have brought back great info and related photos.

    Thats why this is called a forum.

    Rich K.
  • Rich Kontny_3
    Rich Kontny_3 Member Posts: 562
    Hot Rod

    The only thing I would add is that when you reach the condensing point on any heat source (hot air or hotwater) you are now taking acidic flue combustion byproducts and trickling them back through the last heat exchanger to a drain.

    These acidic flue by products are what they are having a hard time handling with various materials you listed. As always you make great points.

  • Bob_75
    Bob_75 Member Posts: 5

    try looking at the ao smith vertex tank.

  • Bart Vaio
    Bart Vaio Member Posts: 56
    Phoenix Water Heaters

    We have real good feedback from our phoenix owners, great reliability so far. Really nice to install and easy to set up. We do not reccommend the Polaris product line due to reliability issues. We have over a dozen phoenix's installed both lp and natural gas. We had also used the Bradford White in the past with good succss as well.
  • ross moore
    ross moore Member Posts: 8
    mod con dependability

    HR -
    You say that jury is still out on the dependability of mod con boilers. You seem comfortable installing them, so is that because most of the failures you see are due to improper installations or applications? Or are they from insufficient maintenance? Or have you found a mod con design that you prefer?
This discussion has been closed.