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Cast Iron vs High Effficiency

Mmacfar Member Posts: 1
Hi all, I am naive when it comes to anything related to plumbing and heating.

We need to replace our 30 year old gas boiler and have had a few quotes. Much debate about HE vs Cast Iron.

1) life span of one vs the other

2)Maintenence required for each and if no maintenence done, does it void the warranty?

3) Overall cost to install

Our house is not particularly energy efficient, not sure if we will make improvements to this.

We live outside Boston -- winters can be mild or horrible (do you read Farmer's Almanac?)

Thanks for any input. Let me know if any other info may be helpful



  • kcopp
    kcopp Member Posts: 3,900
    both have...

    their ups and downs.  You need a contractor to be objective and not just try to sell you something.  Insulation and sealed windows is a key no matter what you do.... That may be your best long term bet... what is there now?
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    HE vs CI

    If you want a piece of equipment that is antiquated and the same efficiency as your old boiler go with Cast Iron.

    If you are interested in saving energy and actually get some return on your investment you will go with High Efficiency.  At least a 30% difference in real efficiency.
  • Bio
    Bio Member Posts: 278
    On the other hand

    1-CI will last almost double as HE if properly installed

    2-CI Yearly maintenance is way cheaper, parts are all the same for CI in any brand unlike HE parts are more expensive and you have to use their brand to work if you can find it local

    3-Over all cost? I think is safe to say CI could be less expensive

    I did my own research and this is what came up with before doing the conversion, HE with 95% is great but the savings you may spend it somewhere else like maintenance, repairs and having to replace it in 15 years?

    Just 2 cents
  • SWEI
    SWEI Member Posts: 7,356

    Will be much better if you can run with outdoor reset control.  Comes included with a mod/con -- adding ODR a CI conventional boiler will significantly increase cost, especially once you add the buffer tank that's needed to get your seasonal efficiency anywhere near the nameplate 83-85% on the boiler.  There are cases where this pencils out -- usually when the existing boiler is OK and a gas conversion is being considered vis-a-vis a mod/con replacement.  Not all mod/con's are the same. A fire-tube design like Triangle Tube or Lochinvar WHN will reduce maintenance and usually allow direct pumping, which reduces both installation cost and monthly electric bills.
  • gennady
    gennady Member Posts: 832
    life span

    why 15 years?
  • CMadatMe
    CMadatMe Member Posts: 3,085

    I love when unknowledgeable contractors use the parts, maintenance and longevity as their argument against condensing boilers. Once you get through the smoke and mirrors you get to the fact that none is true.

    Like any other product a consumer purchases, you get what you pay for. Whether cast iron or not the life expectancy of any boiler is at the mercy of the proper installation and the maintenance (all boilers should be maintained every year). Are there some products that are inferior in quality, sure there are. Its again, a matter of what you pay.

    One poster talked about parts being the same in a cast iron boiler. He must not be up to speed on the new boiler regulations because they are no longer that way. Controls are different.

    I'll take a quality, properly installed condensing boiler over a cast boiler any day of the week.
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
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