Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.

Old house resists high tech

Brant Beach
Brant Beach Member Posts: 17
My old house has oil hydronic boiler in basement with cast iron radiators and steel piping. Single zone. Present system is operational and home is comfortable in winter. Gas co wants boiler with 90% afue min to qualify for interest free loan to convert to gas. My trusted heating pro tells me that from what he has seen, there are no good choices for my configuration, which i don't want to change. He says boiler 90%+ are not as dependable, more expensive to maintain and expensive.
Also showed me how to look at install instructions online and read what the maintenance schedule for these 90%+ boilers would be. Any one know of a more conventional cast iron boiler that would be 90%+ min?

Comments

  • gschallert
    gschallert Member Posts: 170

    Any one know of a more conventional cast iron boiler that would be 90%+ min?

    https://www.williamson-thermoflo.com/products/williamson/gwc-gas-water-condensing
  • Henry
    Henry Member Posts: 988
    Properly sizes and installed Mod-Con boilers such as HTP and Lochinvar are very dependable. They are not more expensive to maintain compared to an oil boiler. SInce you have a cast iron system, they work very well with this type of system. Our experience here up North is that you can save between 25 and 55% on your energy bills.
    ZmanBob Bona_4
  • HVACNUT
    HVACNUT Member Posts: 4,206
    Being a severely biased oil guy, I still have to ask. Does your trusted heating pro also supply your oil?
    Buderus used to offer the G125BE which is a 90% oil fired cast iron boiler. It didn't sell well in the states so it's no longer imported. Maybe there are some still floating around. That being said, a gas conversion with a properly sized mod con boiler, especially with large cast iron rads is a no brainer. You'll want at least a 10:1 turn down ratio, outdoor reset and you'll be very happy.
    Very important to have a proper heat loss calculation done to prevent over sizing of the boiler.
    It would be nice if the contractor services what they install.
    Ask if the technicians use digital combustion analyzers. If not, ask them politely to leave.
  • Brant Beach
    Brant Beach Member Posts: 17
    He is not oil supplier. Has worked on my system piping but present boiler is serviced by oil co. Has installed and serviced gas boilers for other family members in town for 20+ years. What is turn down ratio?
  • Jamie Hall
    Jamie Hall Member Posts: 17,122
    Turn down ratio is a measure of the maximum firing rate of the boiler to the minimum firing rate. The idea is to match the firing rate of the boiler to the actual heating load, which maximizes efficiency. Usually done in connection with "ODR" which is outdoor reset, which senses the outdoor temperature and figures out how much heat is needed to keep the building warm.

    I have no particular brief for oil or gas -- the places I maintain are all oil, but that's because natural gas isn't available. A high efficiency, mod/con gas boiler should work fine for your application -- but only if it is properly sized, nstalled and the controls are properly set up. As is true of many things, even the finest units are junk unless they are used properly!
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • STEVEusaPA
    STEVEusaPA Member Posts: 5,318
    edited June 2017

    ...Has worked on my system piping but present boiler is serviced by oil co. Has installed and serviced gas boilers for other family members in town for 20+ years...

    Doesn't mean he's up on the latest technology. Could also be why he gave this odd statement:

    My trusted heating pro tells me that from what he has seen, there are no good choices for my configuration... He says boiler 90%+ are not as dependable, more expensive to maintain and expensive.
    Also showed me how to look at install instructions online and read what the maintenance schedule for these 90%+ boilers would be.

    You didn't mention what is currently installed, the age or the shape it is in. But if this is true...

    Present system is operational and home is comfortable in winter.

    Why convert at all? There are some very efficient 87-90% oil boilers out there. Properly sized will also save you some money.

    steve
  • rick in Alaska
    rick in Alaska Member Posts: 1,243
    Weil Mclain GV90+ is a cast iron boiler. That boiler has been around a long time, but they just added a secondary heat exchanger to get it to the condensing stage. Fairly time tested boiler.
    Rick
    Solid_Fuel_Man
  • Zman
    Zman Member Posts: 6,994
    It sounds like your old heating guy is resisting high tech. Your house will love it.
    As with anything, some of the early high efficiency models had reliability issues. I would highly recommend any of the newer stainless firetube models (Triangle Tube, Lochinvar, ect). Be sure to give the system a good flush and put in a good magnetic dirt separator with any boiler upgrade in an iron system..
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Paul48
    Paul48 Member Posts: 4,470
    One caveat about the way mod/cons heat vs. a cast-iron boiler. There will be no more piping hot radiators. The aim of the mod/con, running on outdoor reset, is to apply just enough heat to overcome the cold, outside. When done properly the house will be extremely comfortable, but some folks take longer to get used to it. They're use to standing in front of a hot radiator when they come in from the cold, or turning their backside towards it. The amount of money you can save should make it attractive.
  • rbeck
    rbeck Member Posts: 56
    I actually prefer a water tube stainless steel boiler. I also prefer a 10:1 but am not sure you will benefit much from the 10:1 with a single zone cast iron radiator system. Choosing 5:1 or 10:1 I believe in your case is moot.
    You will save more fuel dollars due to proper sizing outdoor reset properly set and proper piping.
    I would probably avoid a 90% cast iron boiler for this application. I believe that the amount of condensate you could produce with ODR and proper sizing could be taxing on a 90% cast iron boiler. The difference between 85% to 90% is is only 5%. is $50 or less a year difference.
  • Brant Beach
    Brant Beach Member Posts: 17
    Thank you all for good info. I need 90% to qualify for no interest loan from Gas Co.to do conversion. Present boiler is Weil McLain P-WGO-4, over ten years old pretty sure. Have to switch to gas heat to get gas run to house. They just installed line in my street.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 10,342
    The boiler you have is probably 82% efficiency, but is it sized correctly?. Use Slant Finn or another heat loss calculator to find the correct size boiler for your house. That is the place to start.

    Once you know that you can make a better decision.
  • flat_twin
    flat_twin Member Posts: 292
    Brant, I have a similar old house (built 1850) with single zone hot water radiators and switched from fuel oil to natural gas last fall. Like you I had to decide between a cast iron NG boiler or a more expensive high efficiency modcon boiler. The additional initial cost of the modcon boiler was almost entirely offset by the fact that we didn't have to repair or reline our brick chimney like we would if we went with the cast iron boiler. The modcon only needed to be vented thru a sidewall with PVC.
    Our 10 cast iron radiators were able to take full advantage of the modcon boiler and allow it to operate at the most efficient low boiler temperatures.
    After seeing 47% actual savings over the previous year in heating costs with fuel oil ($1760 vs $920), I can only say I'm extremely happy with our modcon boiler. It's a Weil McLain Eco 110.
    And, as of last month the Eco boiler and an indirect water heater replaced our old electric water heater which should save about $400 per year on hot water. This programming is already built into the Eco, it's very easy to set up and works very well.

  • Brant Beach
    Brant Beach Member Posts: 17
    I have found a boiler that I think will work. Slant Fin LYNX. Has 95% afue and according to install instructions has low maintenance and good warranty. Anybody have experience with LYNX? Thanks.
  • Zman
    Zman Member Posts: 6,994
    edited June 2017
    I think making a decision based on the maintenance schedule recommended by the manufacture is a deeply flawed approach.
    The lynx has an aluminum heat exchanger. Stainless exchangers have a much better track record than aluminum (Buderous comes to mind) in most installations.

    All the newer mod/cons will qualify for your rebate.
    Fire tube vs water tube seems to be a regional and personal preference.
    Reports heard on this site indicate durability differs with different water conditions. I believe many fire tube failures are do to lack of dirt separation (they just plug up) It does not hurt to ask around for local experiences.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    Bob Bona_4
  • NY_Rob
    NY_Rob Member Posts: 1,370
    Probably less annual maintenance on a modern gas mod-con vs. your current oil fired boiler. And ,except for a Heat Exchanger flush (recommended every 3rd year) it can be done by a competent homeowner at no cost.
    Most of the annual maintenance items are visual inspections and you need to clean the internal condensate trap (15min job- no parts required) and replace the media (mini marble chips $4 for a 10 year supply at Home Depot) in the condensate neutralizer tube. You're looking at maybe an hour to an hour and a half tops to DIY annual maintenance on a modern mod-con.

    A mod-con with cast iron radiators.... it doesn't get any better than that!

  • Steamhead
    Steamhead Member Posts: 14,850
    edited June 2017
    Your heating guy has a point. For generations, people have heard over and over again that gas-fired systems don't need any maintenance. We all know that was to contrast them to oil-fired systems that do need annual servicing (which in a lot of cases is not done right).

    Mod-cons DO require annual maintenance, or they lose efficiency. ISTR that some years ago, @Mark Eatherton , a member of the Wall whom we hold in high regard, skipped maintaining his mod-con for several years and its efficiency went below 70%. That was an eye-opener. Hopefully he'll come on here and fill in the details.

    Last winter we started getting calls on Weil-McLain Ultras that were conking out, and when we asked about their maintenance the owners said "Huh?". Cause and effect. We'll probably be replacing at least one of these soon.

    Then there's the question of how and where we exhaust a mod-con. For all intents and purposes, the exhaust vent (and air intake as well) needs to be at least a foot above the highest recorded snow accumulation in that area, so it won't get blocked in a blizzard when it's needed most and the service truck can't respond. Also, local Codes may require separation distances of exhaust vents from windows, doors etc. that can't be met in a house not designed for this equipment.

    Then there's the question of whether PVC pipe is acceptable as an exhaust method. Some mod-con manufacturers say if's OK to use PVC, but this pipe is not UL approved for this use- just ask the pipe manufacturers. Our company will not use PVC exhaust piping for this reason, especially since there are other materials such as polypropylene and stainless steel which are UL approved.

    In the end, you have to make sure all the i's are dotted and the t's are crossed before you switch to a mod-con. No increase in efficiency is acceptable if it results in an unsafe or unreliable installation.
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • Brant Beach
    Brant Beach Member Posts: 17
    Thanks Steamhead, It seems that having to schedule a start up every year for the modcon boilers is well intentioned but most folks do not read the install instructions through and have no idea of the procedure involved to maintain some of these modcon boilers properly. It makes little sense to save $ on fuel only to spend $ to do the service every year. Also where we are located (while not quite on the moon), we only have one halfassed supply house within 25 miles and if you don't stock parts for every situation, some things will take days to fix. Definitely something to consider when picking an essential piece of equipment.
  • Steamhead
    Steamhead Member Posts: 14,850
    What boiler lines does this supply house carry?
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • NY_Rob
    NY_Rob Member Posts: 1,370

    It seems that having to schedule a start up every year for the modcon boilers is well intentioned but ...

    You don't "turn off" a mod-con during the off season.
    If you have an indirect storage tank for your domestic hot water you need the boiler on 24/7/365. Even if you don't have an indirect, there's still no reason to turn off or shut down the mod-con during the off season therefore no need for a "start up" at the beginning of the heating season.


    ...most folks do not read the install instructions through and have no idea of the procedure involved to maintain some of these modcon boilers properly...

    Whenever I see mod-con install photos- I look for the location of the condensate neutralizer kit (if used). Unfortunately, many seem to install it in an out of the way location. I wonder how many homeowners remember to at least look at the neutralizer media every couple of months? And how many actually remember to service (clean out and replenish the media) on an semi-annual or annual basis?



    HenryCanucker
  • Jamie Hall
    Jamie Hall Member Posts: 17,122
    True, there is no need for startup -- or shouldn't be. In fact, if "startup" includes some sort of flush or something, it will do more harm than good. That said, however, there's no harm to making sure that the combustion adjustments are still correct...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Paul48
    Paul48 Member Posts: 4,470
    Oil-fired equipment, also requires annual maintenance. So you can consider that a "wash". Now you have to look at the savings on fuel. Which could be as much as 40-50%. I think I read somewhere, that if @Mark Eatherton was to install a boiler for you, it would be a high-efficiency boiler.