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Wm gv90+6 with an indirect hot water tank

maybemarkmaybemark Posts: 1,131Member
I am considering purchasing a Weil McLain gv90+6 boiler with just 1 zone. I would like to install an indirect hot water heater. I'm unable to find the instructions for this application in the manual. I see for multiple boilers but not just 1 with a single zone.
I figure I will need 180 to 200f for the domestic hot water, but for my radiators I will only need 140 to160f.
if anyone can help I sure would appreciate it
thanks in advance
mark










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Comments

  • icesailoricesailor Posts: 7,265Member
    Please don't take this the wrong way, but your understanding of advanced Hydronics design needs some polish. The GV90+-6 is a larger sized boiler. In the manual, it clearly states that you can not use the boiler and the internal circulator for zone control, and that about any design you can come up with needs Primary/Secondary piping. If you read and understand what the installation manual says, you can not connect a Indirect, directly to the primary side because the resistance to the indirect may restrict primary water flow and cause flash steaming. When an Indirect is piped properly into a secondary circuit, the boiler and piping only see the indirect as another zone. Any Indirect should be inside the secondary loop.

    What size Indirect are you going to use? Why do you want the boiler High Limit set so high? Are you putting it in a hotel or guest house?

    The GV90+ is just the old GV with that heat recovery unit in the exhaust for the return water to pick up additional heat. The GV is a bomb proof boiler. Like the VHE before it.

    Here's the installation manual. Take notice of the fact that Weil-McLain is selling a fitting to make a "closely spaced tees" connection, fool proof. . Far too many think that any "close" distance is OK. Notice that their drawing used says "Maximum of 12" apart". Then look below at the spacing where it says "As close as possible".

    http://www.weil-mclain.com/en/assets/pdf/gv_plus_boiler_manual.pdf

  • unclejohnunclejohn Posts: 1,362Member
    Why anybody would want that Rube Goldberg looking thing in their basement is beyond me. At least after a 5 or 6 years you can use the heat exchanger for a boat anchor so it's not a total loss.
  • maybemarkmaybemark Posts: 1,131Member
    I'm a general contractor for putting this in my own house, i would be using my plumer to do the instal, and was hoping to get some imput on this. If you want to help, i truely do appreciate it. I am telling you up front, I know alot about different things, but this is far past of what i know. My plumber is old school, and does not like heigh effecincy boilers, i thought this would be like old school boiler on steroids
  • maybemarkmaybemark Posts: 1,131Member
    icesailor
    thanks
    my house is almost 100 years old in chicago, about 2600 sq ft, 2 floors, 1/4 of the house is remodeled with insulation, the rest of the walls have no insulation. All new windows and doors, and 16" of blown in in attic. i was going to get the 55 gal tank
  • maybemarkmaybemark Posts: 1,131Member
    in my head, a cast iron heat exchanger will last a long time, am concerned anything else will be nothing but troubles after a short p[eriod of time with my 100 year old system
  • maybemarkmaybemark Posts: 1,131Member
    Icesailor
    I was told by the techs of WC that i want 180 degrees for the indirect. It's funny, 1 tech says check out page 18 in the manual, and use the indirect as a 2nd zone, another time i call the tech said look at page 26 and use a 3 way diverting valve, and forget about the multiple boilers on that page. i am trying to get an understanding. I am far from being polished on advanced hydronic systems
    thanks
    mark
  • Rich_49Rich_49 Posts: 2,530Member
    edited November 2014
    Here , your old school plumber should like this and so should you . http://www.htproducts.com/pioneer.html
    No complicated piping scenarios which is probably what intimidates your OS plumber , no extra pumps , no nonsense . Tell him this is what you want and be done . this was built just for your situation and it costs less than all the controls , labor and aggravation you will go through with that re labeled WM Gold boiler that did not work the first time and is just as much of a pain in the ass this incarnation . Take a look at Versa Flame for 1 unit space heat and DHW production . http://www.htproducts.com/versaflame.html
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC 732-751-1560
    Serving most of New Jersey , Eastern Pa .
    Consultation , Design & Installation
    Rich McGrath 732-581-3833
  • icesailoricesailor Posts: 7,265Member
    Who are the tech's at "WC"?

    The Installation manual that I posted doesn't show any connections with an indirect. Like I said, it's usually treated as another zone. I don't know why they don't show a water heater connection unless it is because they consider it another zone. Maybe I need to carefully read the manual. As far as page 26 instructions, that applies to multiple boiler installations.

    There are a lot of different ways to control water temperatures in a heating systems. I find it always gets back to price. When the final price comes in, most start looking for ways to save. If you live in a building that is more like a 1800's agricultural building, you're going to need a lot of heat energy to keep it toasty when that Artic Vortex comes a-calling. In Boston, they call it "The Montreal Express". I worked in an area where a lot of GV's were installed. I don't know of any that were ripped out because they didn't work. There were a few really competent people that serviced them. I saw an older GV Series 2 that completely rotted out because they didn't pipe it correctly, didn't do it P/S, connected it to a swimming pool and when the mixer failed, the boiler only ran with 100 degree or less water through a pool HX'er. It rotted away from condensation. That wasn't the boilers fault. Of the hundreds installed, the only service they get is when they stop or don't heat water.

    Those GV/GV-90+ boilers are like the Eveready Bunny. They can take a lickin' and still keep tickin'.

    IMO.

    OBTW, there are professional insulation companies that specialize in blown-in insulation on side walls. The good ones can do it so you can't tell they did it. At least where I was. They drill holes in the outside and fill the cavities. They look for horizontal and diagonal framing members and drill above or below the obstruction. I've seen "gut-rehabs" where insulation was blown in before and there were no hidden pockets with a lack of insulation. Its well worth the expense. Make anyone you consider, have them take you around to multiple jobs they have done. The better ones are really amazing. It really makes a difference in comfort. They take a lot of pride in their work.
  • ZmanZman Posts: 4,813Member
    Why in the world have you decided on this boiler? It won't run at the advertised efficiency at the water temps you are suggesting. Where did you get those water temps? The boiler manufacture could not possibly know what temps are needed without knowing what type of indirect, your hot water needs and the type (and sizing) of heat system you have.
    That boiler is at least twice the size you need. That means much less efficiency.
    If you want to put in a high efficiency unit, don't use your plumber buddy. Have someone do a room by room heat loss calc and design a system that is appropriate for your application.
    Slamming in an incorrectly sized pseudo high efficiency boiler is a total waste.You might as well just do a direct replacement of whatever is there now.
    I would install a high efficiency firetube design like triangle tube. By the age of you system, it sounds like you could run very low water temps and get great efficiency.
    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • maybemarkmaybemark Posts: 1,131Member
    icesailor
    the techs names were dave, then steve, and another one i forgot his name.
    pg 26 is for multiple boilers, but i was told I can use that piping minus the other boiler. Honestly the whole thing mixes me up.
    As far as adding insulation, 3/4 of my house is 2 layers of brick and red clay tile, and plater directly on the tile, no place for insulation.
    I did both, a count of my sq ft of radiators, and a squareft of my house with the updating i did, and it called for about 140 mbh. Here again, maybe i am figuring wrong.
    Plus i had 3 other heating contractors out here not suggesting HE boilers, but told me which GV I would need.
    To everyone else, my plumber is old school and looking out for me. he feels I will maybe get 15 years from any other HE boiler, and spend hundreds on maintanace through out the life time of the boiler.
    I do appreciate other feedback from others. Honestly, i don't know if you right or wrong about the GV 90+.
    To everyone else, who thinks this is a foolish boiler. I appreciate your thoughts. I am thinking long term, and i don't think i will get any long life from these other boilers with aluminum or main manifolds of SS (maybe i am totally wrong)
  • maybemarkmaybemark Posts: 1,131Member
    how hot does the boiler water have to be for indirect tank?
    how hot does it have to be for heating my 13 very large radiators and 3 smaller ones?
  • maybemarkmaybemark Posts: 1,131Member
    Rich
    Your suggestion is a very interesting concept. My Plumber is not afraid of piping a boiler. He is more scared will i get the long life of the boiler verses the money i will be putting out to have effiency. he is in his 60's and is very knolegible on the standard boilers, just when it comes to the HE boilers, he is scared for me, for the initial outlay of money, the anual mantaince, because of the age of my system, and how long will it live>
    Right now i have a 35 year old boiler that is killing me in gas bills. It was sized way to big, and i imagine the effeciency is terrible on it.
    I want to thank everyone who is actually trying to help me
    Mark
  • maybemarkmaybemark Posts: 1,131Member
    with my situation, should i consider the GV90+ and not include the domestic?
    Should i just stick to a standard boiler for long life?
    Should i not be so scared for the HE units breaking down, and high costs to maintane.
    Should i not be scared that a HE boiler will only live 15 years if that?
  • maybemarkmaybemark Posts: 1,131Member
    zman
    when you were talking about slaming, were you refering to me? If so, maybe i said something that you might have been taking as slamming. Actually, i personally am not a fan of people slamming.
    I did have 3 different heating contractors out here, and all told me, i need a 175 input boiler (standard) am i wrong to think I need the same number considering a HE boiler? All the companies that came here were going off of the number of radiators and the sq ft of them.
    Again
    my ears are open for help and opinions, not slamming.
    I like the idea of HE, plus using the boiler for heating domestic, but i want something that will last, without being a problem in the middle of a cold chicago winter
    thanks
    mark
  • SWEISWEI Posts: 7,356Member
    An 80% 175k boiler puts out 140k, which would be 58 BTU's per square foot. Show me the math. I'll bet you can heat that place with a 100k or smaller mod/con. Sizing is based on output capacity, not input.

    As far as efficiency and lifespan, a properly sized and installed modulating condensing boiler should burn 30% less fuel than a typical conventional boiler (without mixed or injected ODR control.) A design based on a firetube heat exchanger will make your old radiators sing. I would add a magnetic dirt separator like the Caleffi DirtMag and flush it regularly for the first couple weeks of operation.
  • ZmanZman Posts: 4,813Member
    By "slamming", I mean just throwing one in without thought.
    Unless it is a steam boiler, the size of the radiators has absolutely nothing to do with the size of the boiler needed. The heat loss of the building is the only factor.
    I would be extremely surprised if you needed a boiler with an input of more than 75,000 BTU.
    If you have generously sized radiators, that makes an even better argument for a condensing boiler.
    I am not sure where you are getting the idea that condensing boilers are unreliable. My Triangle Tube prestige has run flawlessly for 8 years with only regular maintenance.
    Over sizing boilers is horrible for their efficiency and longevity.
    I would suggest getting the opinion of a more knowledgeable heating contractor. The people you are talking to are misinformed.

    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • maybemarkmaybemark Posts: 1,131Member
    SWEI
    I didn't do the math, I am only going by the 3 companies that came here, and telling me. All saying the same thing for the standard boiler.
    I am looking at the output on the gv90+6, the IBR is 140.
    I do appreciate your input, and will look into the products you mentioned.
    I am only going by what the heating people are suggesting as far as size of unit. they certainly could be looking out for their pocket books, and not for mine
  • maybemarkmaybemark Posts: 1,131Member
    zman
    I also read, that measuing the radiators is for only steam, but like i mentioned, the 3 contractors that came to my house for the quotes are all large companies, with good ratings, but huge instation prices.
    Sorry i misunderstood by your word slamming. I am not set in stone for the gv90+, that is why i am asking for help on this site
    again, my house is maybe 2600 sq feet, terrble insulation on the walls, all new windows and exterior doors and blown in insulation in the attic.
    What size unit do you think i should be getting, and is combining domestic with my boiler, is this a good idea?
  • SWEISWEI Posts: 7,356Member
    edited November 2014
    The GV90+ is a condensing boiler made by bolting a secondary heat exchanger on the back end of a conventional cast iron boiler. Some would say that it gives you the worst of both worlds.

    You can almost certainly heat that place with 60-70k of output (DOE) capacity. Start with this and come back with questions. We are here to help.
  • maybemarkmaybemark Posts: 1,131Member
    swei
    thank you for your input. Is this your product, that you are wanting me to look at?
    I am finding out, there is alot of information to can find on the internet, but, you can only trust a a % of the information.
    I did look at the link, but it would not let me come up with information on where to purchase
  • SWEISWEI Posts: 7,356Member
    Not quite sure what you're asking above, but I am not affiliated with Slant Fin or any other manufacturer. We design systems and market a few specialized components, mostly in the controls field. My real product is my knowledge and experience plus a broad range of relationships that reaches across this and several semi-related industries.

    The link I posted (and just corrected a moment ago) is to a free heat loss application you can use to see for yourself what size boiler will be needed to heat your house on the coldest days of the year. With that information, the aforementioned radiation survey, and some idea of your fuel prices, we can help you find the best solution to your problem.
  • maybemarkmaybemark Posts: 1,131Member
    I totally misunderstood, and did not even see the calculator on the link. i am trying to figure it out now
    thank you very much
  • FranklinDFranklinD Posts: 393Member
    I can relate my sizing experience as a homeowner (I have a 101 year old gem up near Duluth, MN, outdoor design temp of -20f). The house is 1700 heated sq ft, some new windows, some original, some blown in insulation in the first floor walls, and a finished (but unheated) 3rd floor.

    We replaced our old boiler (133k btu) with a new Burnham ESC4 which is rated at 78k btu output. Despite punching in all the pretty bad numbers into the heat loss app, our heat loss, at -20* outside and 70* inside, is about 66k.

    After it's performance last winter during 66 consecutive days with a high of zero, I bet we could've gone down to an ESC3 and been just fine. I've read that there's somewhat of a 'fudge factor' built into the heat loss software and that's certainly true in my case. In the case of an Indirect HWH, we're adding one next spring and have no concerns with capacity (it will be a priority zone).

    Don't oversize...take the time to do the proper heat loss. I had a few contractors give me quotes based on measuring the radiators, which would've resulted in us getting the next size up boiler installed, and would've been a total waste.

    Best of luck!

    PS: we also considered the GV90+4, but I decided that it wasn't for us for various reasons.
    Ford Master Technician, "Tinkerer of Terror"
    Police & Fire Equipment Lead Mechanic, NW WI
    Lover of Old Homes & Gravity Hot Water Systems
  • maybemarkmaybemark Posts: 1,131Member
    Franklin
    thank you very much for your input. I m having a very difficult time trying to figure out how to use this calculator for figuring heat loss.
    I'm 60, and tablets and phones are much smarter than me
  • maybemarkmaybemark Posts: 1,131Member
    I am actually starting to get the hang of this calculator. i guess my brain was a little slow. I forsee alot of numbers going into this calulator to get a heat loss
  • maybemarkmaybemark Posts: 1,131Member
    thanks again SWEI
  • maybemarkmaybemark Posts: 1,131Member
    I have about 110000 btu/hr heat loss.
    I used that calculator.
    problem is, i have 12" of brick, with no insulation on the walls.
    So, do i need the gv90+6 or smaller?
  • maybemarkmaybemark Posts: 1,131Member
    I think i made a big mistake on the calculator, my basement is not heated, and i need to figure out a way to have it like that, not 68 like the rest of the house. Doing that will bring that heat loss down alot
  • maybemarkmaybemark Posts: 1,131Member
    SWEI,
    I can not seem to be able to understand how i put my basement as unheated on that calculator of heat loss that you were so very nice to send me the link. If you can help, i would appreciate it
  • maybemarkmaybemark Posts: 1,131Member
    i removed the basement, and came up with a lot smaller heat loss number. 73,200 btu/hr
    if I would consider a gv90+, what size would i need?
  • icesailoricesailor Posts: 7,265Member
    maybemark said:

    I think i made a big mistake on the calculator, my basement is not heated, and i need to figure out a way to have it like that, not 68 like the rest of the house. Doing that will bring that heat loss down alot

    I don't have the calculator you are using, and the old IBR instruction books, being used for instructional purposes, laid out all the theories behind calculation heat losses.

    As far as basements, there is far less heat loss in a basement that people often realize. When you do the walls, you use two numbers. Exposed walls ABOVE grade and walls below grade. The area above grade will be exposed to the same temperature as the outside air. From below grade, the exposure goes from frost at the top to whatever the ground temperature is at the basement floor level. You can have more loss in an exposed living room wall than you do in a below grade cellar wall. Using IBR work sheets and the manual, it was easy to manipulate the odd areas. I was told once by someone that a number of 400 BTU's per Sq. Ft. was a good number to use for floors. I never calculated heat loss through a cellar floor. But I don't think I ever designed a heated cellar and used floor loss. It was for showing someone how little heat loss there was. I think that the exposed wall area was .56 (BTU's lost per degree per sq.ft. same as a 12" uninsulated masonry wall, and below grade was the same as a 2"X4" frame wall with insulation, plywood and sheathing/shingles. Or, .07 BUT's Per Ft. Because the bottom of the wall is around 50 degrees. IBR/University of Illinois Urbana took an average of the wall. I've tried a lot of heat loss calculators. I understand what they are trying to do. I've had a difficult time understanding their conclusions although they come out similar. The Slant Fin heat loss program is based 100% on the IBR method. I can correlate how it works and how to fudge it because I understand the IBR method. I can't with the other ones.

    IMO, there's no "Fudge" in the numbers. Its done through the designer and the manipulation of factors. By calculating less insulation or more heat loss. It isn't done in the program. When I moved, there was a box with all my treasured information in it. Somehow, it ended up in a dumpster because when I got to Florida, it wasn't there.

  • maybemarkmaybemark Posts: 1,131Member
    i removed the basement, and came up with a lot smaller heat loss number. 73,200 btu/hr
    if I would consider a gv90+, what size would i need?
  • ZmanZman Posts: 4,813Member
    If you were to purchase and install that thing, the GV90+4 would be the appropriate size.
    You do understand that unless you buy a separate outdoor reset controller, you will never exceed 84% efficiency.Given that it is a simple on off boiler and cannot modulate, that will reduce your net efficiency into the 70's%.
    You should also be aware the condensing technology and cast iron are inherently incomparable. The condensate wants to eat the boiler.
    The ratings on boilers in general are deeply flawed. The test is done in conditions that are no where near real world. Modulation is not factored in at all.
    I would either buy a nice firetube real condensing boiler like the triangle tube prestige or lochinvar WHN or just buy an appropriately sized standard cast iron boiler. Either one is a much better choice than the GV90+.

    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • maybemarkmaybemark Posts: 1,131Member
    carl
    My plumber friend doesn't think I will get more than 15 years from a high effecient boiler (aluminum or SS manifold) plus, my 100 years of sludge in my lines, which we have all intentions of trying to remove as much as posible. I do appreciate you input very much, and i will look at the TT prestiguge. (what size should i consider)
    My plumber is just looking out for me. If it would be up to him, he would put in a standard boiler, but i was hoping to have domestic hot water from my boiler also.
    All who have helped me with my project, i hope you all have a good turkey day
    mark
  • ZmanZman Posts: 4,813Member
    The prestige 110 would be slightly oversized. For a 1 zone system it would work well because it modulates. The Lochinvar WHN85 would be right on. The new firetube boilers are much less prone to plugging than the older giovanni style. I would still give the pipes a good flush and install a high quality dirt separator.
    I also don't think that a standard cast iron unit is a mistake. Look at your gas bills and decide if saving 10%-20% is worth while.
    Either unit is capable of making domestic hot water through an indirect tank.
    Carl
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • maybemarkmaybemark Posts: 1,131Member
    was i right on thining, not to include the basement, since it is not a heated area, when i made my calculations?
    I live in chicago, I live in a house that is 90+ years old. My walls are 2 bricks, with clay tile, then plaster directly on the clay tile. When i remodeled my kitchen 20 years ago, i properly insulated the area, but this is about 1/8 of my house. The house is around 2600 sq ft with several cast iron radiators( not baseboard heat).
    My natural gas bills are killing me, I am on a budget, right now, it is up to $241.00 per month, every month. I need to do something. I am not set on the gv90+, i just thought this would be good for me, since it seems to be forgiving for the age of my house, plus it has such a high warranty on the heat exchange.
    My ears and head are still open to suggestions. But I need to do something.
    Idealy, the indirect water heater sounds like a huge savings also, in the long run
    thanks again everyone, for your help and input
    mark
    happy turkey day
  • SWEISWEI Posts: 7,356Member
    A Lochinvar WHN085 would be my choice here as well.

    The fine print in boiler warranties generally ensures that you don't end up with much when something goes wrong. You're going to spend a LOT more on fuel than the cost of any boiler over a 15-20 year lifespan. In 20 years, who knows what kind of heat source(s) we will all be using?
  • maybemarkmaybemark Posts: 1,131Member
    swei
    am i thinking proper not to include the basement on the calculator you suggested i use, since it is not a heated area?
  • Rich_49Rich_49 Posts: 2,530Member
    Do not include the basement and also make sure that for the first floor you enter area below not heated and then enter the average temp of the basement .
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC 732-751-1560
    Serving most of New Jersey , Eastern Pa .
    Consultation , Design & Installation
    Rich McGrath 732-581-3833
  • maybemarkmaybemark Posts: 1,131Member
    Rich
    I did go ahead an not included the basement, and i did enter the floor with the underside being an unheated area. i did not notice where to enter the average temp of the basement, so that is not considered in my calculations.
    If you don't mind me asking, what unit would you recomend?
    I have been reading up on the suggestions of others. i was hoping to be able to do the mantainance by myself, but the manuals are saying to hire a professional to do it. I am not a professional at hydronic systems. i also on SS, with a very small income. i do not have pockets overflowing with money.
    I am wondering if my plumber friend is right, and just go with a standard boiler.
    It's too bad, because i really was hoping to include DHW with my system
    happy turkey day
    mark
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