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Replacing 1966 gas boiler! HELP!

Hi everyone. Our '66 boiler is leaking so we are in the market for a plumber to replace it. A few questions:

1. We have a 3000 sq foot house with 172 feet of baseboard heat plus 3 kick heaters and one 4 foot radiator. One plumber is telling us to get a 100,000 btu boiler and another plumber is saying to get a 140,000 btu boiler. What do you think?

2. We are deciding between a Peerless and Weil Mclain. Any thoughts? My understanding is both are good.

3. We are also going to get an indirect tank for water. One plumber says to go with a Burham that is "stone lined" because we have hard water and that will be less susceptible to problems from the hard water. True?

4. Last: Most plumbers are trying to sell us a 82" efficient boiler. Is it worth getting something more efficient?

Thank you!!

Comments

  • lchmb
    lchmb Member Posts: 2,997
    1. Get a complete heat loss done...do it once, do it right..I'm guessing the house has been upgraded since 1966 and unless done your guessing...

    2. Both are good products...depends which your service tech is comfortable

    3. Treat your water would be the first recommendation but again, tanks seem to be weak or strong based on an area.

    4. They are going with something that generally requires less maintenance but you give up some efficiency...guess the biggest thing is what's most important to you...90% plus requires more service in the long run but can save you money every winter (as long as it doesnt have issues)...

    Good luck..
    Rich_49
  • John Mills_5
    John Mills_5 Member Posts: 935
    There likely would be a huge price diff between the simple 82% cast iron boilers and the complex 90%+ boilers that require special piping. If you had a converted gravity system or infloor radiation, payback would be faster. With the hotter temps of baseboard, savings may not be that great. If you get a price both ways, look at potential savings. While a boiler may say 95% efficient, if water temp is above 140, it isn't condensing and closer to 85% at those times. You may spend a bundle and not realize the savings. And I like what lchmb said in his last few words!
  • MikeSpeed6030
    MikeSpeed6030 Member Posts: 69
    Where do you live? 140,000 Btu/hr may likely be oversized. As previously stated, you must do a heat-loss calculation for your house.

    Personally, I would opt for the less efficient and simpler boiler. I would also prefer a stand-alone gas-fired hot-water heater over an indirect that is tied to you heating boiler. 40-gal gas water heaters are reasonably priced and should last 20 years or so if you periodically drain a bucket of water from the heater to remove sediment - and you don't have to run your boiler during summer months...and when your boiler is down for maintenance, you still have domestic hot water.
  • Aaron_in_Maine
    Aaron_in_Maine Member Posts: 315
    You should do a heat loss calculation on the house. That will tell you what size boiler you need. You have 100,000btu worth of baseboard so the 140,000btu boiler is oversized. The 100,000btu boiler is probably too big as well. The only way to really know is to do a heat loss.
    Aaron Hamilton Heating
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  • MikeSpeed6030
    MikeSpeed6030 Member Posts: 69
    Where is you boiler leaking? If it's the heat exchanger itself, then I would agree that it's replacement time. But if the leak is somewhere else, e.g. near-boiler piping, then hold off. Posting Pix would be helpful.

    You may think your 1966 hot-water boiler is old. Mine was installed in the early 1950s, and is still going strong.
  • jonny88
    jonny88 Member Posts: 1,139
    I would stay away from the alliance(btw) not made by Burnham .Actually a Vaughn product but you can pay extra for a Burnham jacket .3/4 coil takes a long time for recovery.Interesting post by @EzzyT lately where he installed a HTP Pioneer.Check it out,they got a lot of nice products on the market.
  • unclejohn
    unclejohn Member Posts: 1,749
    With mostly baseboard I would stick with nthe cast iron.
  • Ironman
    Ironman Member Posts: 6,563
    As others have stated: do a heat loss calculation. SlantFin has a free app that you can download from their site that's easy to use. The heat loss calc IS the foundation for every aspect of design and sizing.

    You can basically figure that standard 7" fin tube baseboard has an output of 500 btus per foot of ELEMENT @ 170* average water temp. Don't use 180* specs: that's not the AVERAGE water temp in your system unless you supply it with 190* water. The toe kicks could be anywhere from 5 to 10k but output each; check their model numbers to confirm.

    If the load calc indicates that you BBs are oversized, then the supply water temp can be lowered accordingly. This is critical to know in making a choice between an 82% efficient cast iron boiler vs. a 95% mod/con. The mod/con's efficiency rises as the water temp is lowered. 95% is an average number, not a constant.

    The mod/con has a feature known as outdoor reset (ODR). This adjusts the water temp to meet the actual load conditions. The warmer it is outside, the lower the water temp needed to heat the house. You only need 180* water on the coldest night of the year (design condition). ODR can easily cut 15 - 20% in fuel usage, but that number is NOT reflected in the efficiency (AFUE) rating of the boiler.

    If your load calc and local weather data indicate that the boiler could spend the majority of the season producing 140* or less water temp, then the mod/con would be the more more efficient choice by far. But, it comes with a higher price tag.

    There's also another caveat here: most plumbing and HVAC contractors don't know how to properly install and service mod/cons. That's why they push the old cast iron technology. Do your homework on choosing a COMPETENT hydronic contractor and follow his recommendations. There's a contractor locator on this site. I'd recommend trying that or posting your locale and asking for a recommendation.

    One more thing: if you go with a mod/con, the toe kick heaters will need their aquastats changed out with low temp ones. This is a relatively inexpensive thing.

    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Counselor4444
    Counselor4444 Member Posts: 3
    Hi
    Thank you all for the responses.

    I found a heat loss calculator online. I'm going to try to do that myself. We have lived in our home for a few years. We've done a lot of work to it. We have new insulation in the attic, all new Andersen 400 series windows, we just removed the cedar shakes and had foam insulation and vinyl siding put on and we did renovation work in some rooms and those have new exterior wall insulation.

    Our '66 boiler is leaking from the bolts/connection that takes the water into the boiler tank. We've had a few plumbers here to look at it and everyone agrees that there is high risk in trying to replace them since they are very coroded. Everyone is warning us that it is unlikely it will withstand the repair. And it is winter here and we cannot go with heat.

    We definitely think we'll be going with a less efficient 82% boiler. The higher efficiency ones will not pay off and since we use natural draft now it doesn't pay to pay more to have them run pvc pipes to vent a 90% efficient boiler. Plus by all accounts the more efficient ones seem to require more maintenance and be more prone to issues with sensors and other features.

    So, we still need to figure out what size boiler to get. And still considering the water heater.
  • Tom_133
    Tom_133 Member Posts: 773
    Counselor4444,

    You are on the right track, do your heat loss. When you get the results post them here. One problem when asking hundreds of professionals their opinions, is you will get many, many differing opinions. The one constant here though is first, do the heat loss.
    Second, make sure you fully vet the heating company you choose to quote your system. Have them show pictures of past jobs, talk to some of their other customers. Heating systems are not cheap and you want yours to be right. Third, Everyone here on the wall wants your final product to be reliable, safe, clean and as efficient as it can be for your application. Unless this is an emergency, put in the time and get it right.

    Tom
    Montpelier Vt
  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083
    edited January 2016
    The $ you may save on a stone age boiler will vanish and then some when you find out a 50 year old masonry chimney needs a liner. There's more to the boiler cost equation when comparing.
    IronmanBrewbeerSWEIegansen
  • Ironman
    Ironman Member Posts: 6,563
    edited January 2016
    Bob Bona said:

    The $ you may save on a stone age boiler will vanish and then some when you find out a 50 year old masonry chimney needs a liner. There's more to the boiler cost equation when comparing.

    I totally agree with Bob. Don't let any contractor tell you that your chimney doesn't need a liner. A new boiler 80% boiler, because it produces much lower stack temps, will require that your masonry chimney have a stainless steel liner. If it's on an outside wall, the liner will also have to be insulated. Failure to do this will cause flue gas condensation in the chimney which will in turn attack the mortar joints and eventually cause the chimney to collapse internally. I've seen it happen many times from this very scenario.

    PVC pipe (or even PPL) will be much less expensive than lining your chimney.

    As far as maintenance and repairs on mod/cons goes: in the years that I've been doing them, I haven't seen any appreciable difference. A cast iron boiler requires as much maintenance as a down-fired fire tube or helix coil mod/con. Trap cleaning being the minor difference. Others may have different experience and opinions, but that's mine. Of all the mod/cons we've installed, we had a service call on only one of ours so far this season and that was because someone closed the valve on the water feed line - nothing in the boiler. We see constant service calls on cast iron boilers, most all of which have been expensive.

    I think a lot of the talk about mod/cons costing more to maintain has come from improper installs, flawed earlier designs and lack of competency with many "technicians" that attempt to service them.

    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    Bob Bona_4SWEI
  • Counselor4444
    Counselor4444 Member Posts: 3
    Hi all
    Finally an update. We made it through the winter with the old boiler and are now looking to replace it. We did the BTU calculators and we should be getting a 140k-150k boiler.

    Most plumbers are saying we probably won't need a liner ($800ish) anytime soon because our chimney is in the middle of the house. We are leaning towards getting a82% efficient unit. The cost savings in getting a more efficient unit we'll never see and everyone says more of a pain to maintain.

    Thoughts? Thanks
  • Robert O'Brien
    Robert O'Brien Member Posts: 3,385

    Hi all

    Finally an update. We made it through the winter with the old boiler and are now looking to replace it. We did the BTU calculators and we should be getting a 140k-150k boiler.



    Most plumbers are saying we probably won't need a liner ($800ish) anytime soon because our chimney is in the middle of the house. We are leaning towards getting a82% efficient unit. The cost savings in getting a more efficient unit we'll never see and everyone says more of a pain to maintain.



    Thoughts? Thanks

    No way is a 3000 sq/ft house 150K, maybe half that, just maybe.
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  • Paul S_3
    Paul S_3 Member Posts: 1,257
    my home is 4200 sq ft and i have a 110k boiler ....who did your heat loss? if the plumber did it ,looks like he used 50btus per sq ft as a rule of thumb which is double what you need... and run a liner
    ASM Mechanical Company
    Located in Staten Island NY
    Servicing all 5 boroughs of NYC.
    347-692-4777
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  • ChrisJ
    ChrisJ Member Posts: 11,974
    Why would the chimney being in the middle of the house be related to whether or not it needs a liner?

    Wouldn't you want one even more under those conditions?
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
    njtommy
  • JUGHNE
    JUGHNE Member Posts: 8,949
    They assume that a central of house chimney is a warm chimney and a happy chimney. Only maybe the last 10' may be in the attic and above the roof and condensing exhaust gases. But with the warm chimney, there is enough momentum for gases to continue up and out. Less efficient equipment usually guaranteed this to happen. Now it is border line if there is enough heat lost up the pipe to ensure its transport. IMO a liner (flex slinky liner) will keep the gases together to concentrate their effort to escape the chimney to the atmosphere by means of thermal buoyancy.
    Just think of all the "orphaned" water heaters left to fend for themselves in a huge masonry chimney. They are lost gases and probably cling to the sides of clay liners (their hosts) and/or bricks and devour the wall they hang on. Such a tragedy occurs when the house heating appliance is removed from the chimney and vented outside with PVC or such. (My wife just read this and describes it as a "rant")

    However I digress: my last 2 boiler changeouts ended up being Modcons because the masonry chimneys were so bad you would not want to go onto the roof and hang on the bricks for support. Both of these were such that a higher efficiency CI would have done justice to the project. But both were beyond liners. A new "B" vent was out of the question because of existing floor plans.
    ChrisJ
  • Danny Scully
    Danny Scully Member Posts: 1,329
    The chimney being in the middle of the house means it isn't as likely to condense because of the conditioned space it runs through. A lining, however, is never a bad idea.
    ChrisJ
  • jonny88
    jonny88 Member Posts: 1,139
    IMO a liner should be sized for new appliances to ensure drafting etc.Inspectors require it for what its worth
  • KC_Jones
    KC_Jones Member Posts: 4,831
    140-150k?! That is definitely too big, it will short cycle like crazy. I think someone mentioned already your baseboard can only output roughly 100k BTU. Has nothing to do with heat loss, but it shows the maximum capability of your system plus the toekicks. You need to look at your heat loss numbers again.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    Canucker