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New LP Boiler options, any opinions?

isaacleonard1
isaacleonard1 Member Posts: 21
edited August 2020 in THE MAIN WALL
I am currently getting bids on replacing my old fuel oil boiler. I am switching to LP. About 110ft of baseboard in ~2000ft house. Will not be using my unit for hot water at this point. The heat load on the house says about 60k BTU needed if I wont be using it to heat my hot water.

I have gotten quotes for:
Bosch 79kBTU 95% High Efficiency
NTI 110kBTU 95%
Slant/Fin 90kBTU 84%
Burnham 105kBTU 84%
New Yorker 105kBTU 84%

Prices are everything installed. Comparing between them, any opinions on which may be a better/more reliable option and why? I am leaning towards one of the 3 cast iron options.

Thanks

Comments

  • hot_rod
    hot_rod Member Posts: 22,022
    Looks like the Bosch and NTI are mod con, the others are conventional boilers?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Ironman
    Ironman Member Posts: 7,367
    Please remove the pricing, it's against site rules.

    Put your efforts into researching the contractor, he's 98% of the equation.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    isaacleonard1Erin Holohan Haskell
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,720
    edited August 2020
    @isaacleonard1
    please read the rules of this forum. The prices should not be in your post/

    You can say
    Boiler #1 is 95% AFUE at $$$$
    Boiler # 2 is 95% AFUE @ $$$
    Boiler number 3, 4, and 5 are 84%AFUE Cast Iron at $

    should I spend over $1000 more for at 95% and why?
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    isaacleonard1Erin Holohan Haskell
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,720
    When using fuel cost use gallons or therms, not price of fuel.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
    isaacleonard1
  • isaacleonard1
    isaacleonard1 Member Posts: 21
    hot_rod said:

    Looks like the Bosch and NTI are mod con, the others are conventional boilers?

    Yes that is correct
  • hot_rod
    hot_rod Member Posts: 22,022
    I'd go with one of the mod cons, they will have many useful features like modulation, output limiting, outdoor reset, datalogging, etc.
    Much of the heating season could be supplied with low temperature supply to take advantage of the condensing mode operation.
    Features depend on the model you choose of course.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • isaacleonard1
    isaacleonard1 Member Posts: 21
    hot_rod said:

    I'd go with one of the mod cons, they will have many useful features like modulation, output limiting, outdoor reset, datalogging, etc.
    Much of the heating season could be supplied with low temperature supply to take advantage of the condensing mode operation.
    Features depend on the model you choose of course.

    Yes, I am still considering. The Burnham from installer #2 said he can add an outdoor reset for just a few hundred bucks. If I do decide to go cast iron, that may be something to consider?
  • hot_rod
    hot_rod Member Posts: 22,022
    What type of heat emitters? Is the system zoned?
    Yhe efficiency gain is only seen when the boiler is running low temperatures and condensing. The type and numbers of emitters has something to do with your selection. Can they run low temperatures enough of the season to offset the cost difference.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Jamie Hall
    Jamie Hall Member Posts: 23,168
    Installer installer installer. Plus what @hot_rod said. The best boiler in the world installed on the wrong system is not going to be good for you. The best boiler in the world installed by a person who doesn't really know what he or she is doing, and who isn't going to be there for service (especially mod-cons) is a catastrophe waiting to happen.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,720
    edited August 2020
    @isaacleonard1 Said:
    "Yes, I am still considering. The Burnham from installer #2 said he can add an outdoor reset for just a few hundred bucks. If I do decide to go cast iron, that may be something to consider?"

    CAUTION Cast iron boiler will have a problem with outdoor reset when operating below the minimum temperature recommended by the manufacturer. That is usually 130° minimum return water temperature. The water temperature needed for heating in the spring and fall will be as low as 110° or 120°. so the benefit of outdoor reset will be minimized compared to that of a ModCon.

    Also, the benefit of a Modulating boiler is that once your heating need is greater than the minimum turndown rate (when the outdoor temperature is like 50° outside) the boiler does not turn off. the fire in the boiler just increases and decreases as needed to keep your home warm.

    Think of it like cruise control for your heater. Your cast-iron lower-priced heaters turn on or off by the thermostat. This is like driving your car with no accelerator pedal. Imagine driving down the highway with just the ignition switch. On is full throttle off is ...Well OFF. So to get to 55 MPH you turn the key ON (full throttle). When you get there at 55 MPH you turn the key OFF. Of course, the car will immediately begin to slow down. If you are going uphill (like a cold day) you will slow down faster. If you are going downhill (like a warm day) you will slow down slower. NOW when you slow down to say 45 MPH, turn the key ON (full throttle). When you get to 55 MPH then turn the key OFF. Keep driving like that for an hour and see how aggravating that would be. (and also waste fuel)

    That is how your old heater operates, and that is how the new cast iron boiler will also operate.

    The Modulating, Condensing (MocCon) boiler has 2 operating cost lowering features. #1. Is the modulating feature. This feature eliminates the OFF / ON cycling by changing the size of the flame inside the heater based on several factors including the outside temperature (directly or indirectly). As the outside temperature gets lower the flame is increased, as the outside temperature gets warmer the flame is decreased. This reduces the On/Off cycles that waste fuel. (A boiler is at its greatest efficiency after it operated for at least 3 to 5 minutes.)
    # 2. Is the ability to accept lower temperature return water. It actually operates more efficiently with lower return water temperatures.

    So, if you plan on keeping this home and heater for 5 or more years, your operating savings may be more than the additional $$ spent on the new boiler.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,720
    hot_rod said:

    What type of heat emitters? Is the system zoned?
    Yhe efficiency gain is only seen when the boiler is running low temperatures and condensing. The type and numbers of emitters has something to do with your selection. Can they run low temperatures enough of the season to offset the cost difference.

    If your Radiators are the old cast iron ones that have a large water volume, the Mod Con will operate more efficiently.

    If your radiators are the baseboard type with the copper pipe and aluminum fin elements, the Mod Con boiler will not operate at the lower more efficient temperature for as long as it would on the cast iron radiator system.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • isaacleonard1
    isaacleonard1 Member Posts: 21

    hot_rod said:

    What type of heat emitters? Is the system zoned?
    Yhe efficiency gain is only seen when the boiler is running low temperatures and condensing. The type and numbers of emitters has something to do with your selection. Can they run low temperatures enough of the season to offset the cost difference.

    If your Radiators are the old cast iron ones that have a large water volume, the Mod Con will operate more efficiently.

    If your radiators are the baseboard type with the copper pipe and aluminum fin elements, the Mod Con boiler will not operate at the lower more efficient temperature for as long as it would on the cast iron radiator system.
    Thank you for all the great information above. I now understand why the outdoor reset on a cast iron is not as effective. I am wondering though will the added complexity cause my savings to be offset by the chance of needing extra repairs. I probably do plan to be in the home for 5+ years.

    In the house I do have about 110 ft total of copper pipe and aluminum fin baseboard if that changes anything.
  • Here in the Bay Area, cast iron boilers are not allowed, but I sure wish we had access to them for some of our jobs, especially where low mass, high temperature heat emitters are in place, like your copper tube, baseboard.

    I was never enamored with mod/cons in this situation. Sure, save a bit on fuel, but these new mod/cons are very fussy, with a LOT of sensors and safeties along with the fact that you now have to deal with condensate with its own set of problems. During the heating season, most of my work is service and repair and it’s mostly on mod/cons. I would rather spend more on fuel than on repairs as repairs will wipe out fuel savings in one service call.

    Besides, cast iron, atmospheric boilers will last you 30-40 years and mod/cons will give you 15 years.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
    SuperTech
  • isaacleonard1
    isaacleonard1 Member Posts: 21

    Here in the Bay Area, cast iron boilers are not allowed, but I sure wish we had access to them for some of our jobs, especially where low mass, high temperature heat emitters are in place, like your copper tube, baseboard.

    I was never enamored with mod/cons in this situation. Sure, save a bit on fuel, but these new mod/cons are very fussy, with a LOT of sensors and safeties along with the fact that you now have to deal with condensate with its own set of problems. During the heating season, most of my work is service and repair and it’s mostly on mod/cons. I would rather spend more on fuel than on repairs as repairs will wipe out fuel savings in one service call.

    Besides, cast iron, atmospheric boilers will last you 30-40 years and mod/cons will give you 15 years.

    Thats exactly what I am thinking, one service call and all of my savings could be offset. Let alone multiple calls. Not even considering the expected lifespan of the unit.
    SuperTech
  • Ironman
    Ironman Member Posts: 7,367
    The new cast iron boilers have almost as much complexity as mod/cons and we see more frequent repairs on them. The block may last longer than a mod/con, but that's the only significant difference that I see.

    Also, a new cast iron boiler is more efficient than an old and produces cooler flue gasses. That will REQUIRE a stainless steel chimney liner - you cannot vent it directly into a masonry chimney. A mod/con can use PVC or PPL and be vented through a side wall.

    For these reasons will seldom install cast iron boilers on hot water systems.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.