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Navien Combi vs. Budurus vs.Burham EC2

sachmo Member Posts: 7
Reposted from DHW area. Thanks in advance for your help.

I am a homeowner with a choice between 2 options and would like to hear some advice/options on them.

I have a 2800 sq ft 1957 split house in NJ with decent insulation, updated windows etc, with natural gas powered AO Smith water heater and a 1973 100K BTU Utica boiler. There are 2 zones of baseboard (1st/Basement and 2nd floor). It has 4 BR, 2 BA, 1 Kit, 1 LR, 1 DR

We had a flood that killed the units and I have 2 quotes with differing technologies.

Quote 1: Navien Combi unit vented to side wall providing heat and DHW, new pumps and other items $6200

Quote 2: Burdurus 100 BTU Bud GC 124/411 gas water boiler and Bud S120 32 gal. indirect HW tank (and pumps etc) $7350

Quote 3: Burham ES2 with non-specificed indirect tank $6200

The house will likely be a residential rental, and I would like a reliable, good performing system that will just run. Both installers seem competent and know their materials and craft.

I would lean toward the Navien, but my concerns are maybe:

- not enough power to heat house during very cold spells (0-20F)

- with the on demand DHW be able to support a 5 person family with showers, laundry, etc...

- is this unit and technology mature enough to be reliable and a good performer?

- DWH lag - will i be waiting for DHW everytime i want to wash hands?

The burderus is reputable brand and I have an indirect setup in my own home (munchkin and TT), which basically has unlimited DHW. My concerns are:

- cost, my problem, but it is more expensive

- additional cost if we need to get a chiminey liner (TBD)

- more parts to the system to break.

So, I would appreciate your views on this. Is there a better solution in the same or less pricepoints?

But any feedback to help me decide would be much appreciated.


  • kcopp
    kcopp Member Posts: 4,188
    Talking prices....

    here is a No-No.... that being said the Navien and the Buderus/ Burnham boilers are completely differnet animals.... Chimneys are reliable. The wall hung gets the boiler more off the floor so that a repeat flood is less likely to kill another unit.... may want to ask about a wall hung that is not the Navien.... I have not read a lot great things on them.
  • sachmo
    sachmo Member Posts: 7

    Thanks for the info, Im not asking for opinions on price, more about what I should get technology wise for that price "range".

    What other wall hung units would you recommend? would you recommend a combi technology, or a mod-con wall hung?

    are there any in a similar budget range as the navien that might be something to consider?
  • CMadatMe
    CMadatMe Member Posts: 3,086
    None of the Above

    Wouldn't choose any of these. There is no mention of a heat loss. Sounds like someone just looked at the label of the old Utica and picked the same btu/hr output boiler. Heat loss of a home of your size in NJ is going to be less then 60,0000 btu/hr.

    I wouldn't choose the Buderus because the heat exchanger is aluminum. The Navien in my view is just a super charged water heater that over time will wear down from the beating of doing a boilers job. The Burnham is a great cast iron boiler but condensing is where the efficiencies are and this boiler doesn't condense.

    A btu is a btu and any condensing wall hung boiler can handle the job of heating the home in your climate. Personally would look at doing either a Viessmann Vitodens 100 or Triangle Prestige Trimax.
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • kcopp
    kcopp Member Posts: 4,188

    pretty sure a Buderus 124-II 4 is a cast iron boiler.... I just installed one last week. A G142 is aluminum. Since it is a rental property there is a good chance a mod con is out of his reach. A Biasi Riva is a decent wall hung that is not a mod con.....
  • JohnHenry_2
    JohnHenry_2 Member Posts: 70
    edited October 2012
    Hey Chris,

    Question for you about the Navien. You've on more than one occasion stated that the Navien combo units will wear out prematurely "doing a boilers job". Can you tell me why, in mechanical or engineering terms, you think this is true? Is there some inherent flaw in the design that you know of? Is the heat exchanger material too thin or of poor quality?

    Or are you merely speculating and assuming facts not in evidence?

    During my training as a mechanical engineer, I was taught that what wears things out is cycles. Mechanical load cycles, pressure cycles, heat cycles etc. A car engine, for example, experiences 90+% of it's wear in the first minute after start up. So staring a car from cold and driving it 2 miles has essentially the same engine wear as starting it from cold and driving it 200 miles. An on demand water heater will have many heat cycles when one is doing the dishes and turning the hot water on and off. Or washing the dog.

    A properly set up heating system will have far fewer cycles than an on demand water heater. This is particularly true with the Navien units as they come with outdoor reset, a 10:1 turn down ratio and fairly sophisticated anti short cycle control logic to avoid short cycling. The anti short cycling control logic is especially useful during the shoulder seasons. Also remember that with that huge turn down ratio most of the time this unit is doing long run times at a very reduced firing rate. Last winter during the cold months my Navien CH-210 ran pretty much all the time (no more than 2-3 cycles/day) with minimum 2hr run times. And the unlimited hot water is the shiznit...

    That said, the Navien might not be the best choice for the original poster since he has baseboard heat. If the amount of radiation requires 180* supply at design temp there could be issues as the unit will shut itself down if the exhaust temp gets above 149*. 160* return will cause 160* exhaust temps. If he has more insulation and a tighter seal on the house than when it was built, it's likely this unit will work just fine, design wise.

    Chris, I eagerly await your reply!
    The bitterness of poor quality remains long after the sweetness of low price is forgotten.
  • sachmo
    sachmo Member Posts: 7
    more confused

    Thanks for you input.

    I'm more paralyzed by my decision based on John Henry's note.

    From a pure functional point a view, if a Navien worked reliably and correctly for my baseboard and will last, then it makes sense. But I have no way to figure that out.

    The Budurus conventional is the same price, but 85% and old school (reliable, but more expensive to run?) If I go this route, I could go to a lower cost old school boiler (Weil or some other non-premium brand).

    The Navien vendor did not measure anything, just looked at the house.

    The Budurus vendor measured the length of all the radiators but won't tell me the heat load.

    Frankly, the lack of transparancy is annoying. If anyone can afford me some advice, or for that matter, can come and do the professional real estimate I see the members of this board do in the Union County NJ area, please send me a message.

    I did use "find a contractor" and got no replies.
  • JohnHenry_2
    JohnHenry_2 Member Posts: 70
    Sorry for the confusion.

    It's not that I'm advocating for any of those units for you. I just take issue when statements are made regarding products with no evidence to corroborate said statement. That said, the Navien unit is pretty new to the market and the lack of empirical evidence as to it's longevity will keep many people from using it. It does have a 10 year HX warranty which made me comfortable enough to buy one. You do get a lot of technology for the money. I'm coming into my second heating season with the unit and i couldn't be happier with it. We'll see how it works out over the next 10-15 years or so. Your mileage, of course, can vary.

    Back to your choice of gear. As is repeated on this board daily, you must get an accurate heat loss for your home. If you can't get that info from one of your suitors, do it yourself. It's not very difficult and if you're a nerd like me, you may even enjoy it. Then you need to measure the amount of radiation you have. With that information you'll be able to discern what temperature your water will need to be for design day conditions.

    THEN you can figure out which units will work for your home's parameters.

    Maybe your local energy company does "home energy audits" that could include a heat loss calculation?

    In defense of the guy that bid the Navien without doing a heat loss. He probably knows that it has a huge turn down ratio and will burn as little as 20K BTU/hr and as much as 200K BTU/hr. That unit will turn down as low or lower than anything else that will heat a home that size. What he didn't do was to make sure the unit will even operate in the parameters that your house needs to run in.

    I think the bottom line with anything technical and expensive is to find a guy you feel comfortable working with. Sometimes it takes months and not inconsiderable effort to find the right guy. But it's worth it. This is probably one the top 5 or 6 most expensive relationships you'll ever have (after wife, realtor, car mechanic, jewler) so it's one that should be carefully gotten into.

    If I didn't have a hard stop budget, I'd have gone for a Lochinvar wall hung with a double shell indirect...

    As always, "ain't nothin' a bargain unless you want it".
    The bitterness of poor quality remains long after the sweetness of low price is forgotten.
  • gennady
    gennady Member Posts: 839
    edited October 2012
    boiler choice

    I always answer customer question about boiler choice with notion that it is not about the boiler, it is about installer they have to worry. Unqualified installer will screw up any boiler. I would recommend on tight budget installation of simple cast iron boiler with no complications, and tank type gas fired water heater.
  • gennady
    gennady Member Posts: 839
    edited October 2012

  • sachmo
    sachmo Member Posts: 7

    We ended up with an installer who gave us a reasonable estimate, was upfront about pros and cons and heat loads etc... and we are getting a weil gc4-e with a weil indirect vented out the side to avoid any chimney liner issues prevalent in our town.

    Thanks for your help

This discussion has been closed.