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Boiler replacement with DHW coil advise

VBdiver
VBdiver Member Posts: 2
I purchased a 1962 brick ranch 1800 sq ft , 2nd owner 2yrs ago . It originally had an oil fire boiler , long since gone . The previous owner replaced it with a Burnam Electric wall mount to heat hot water baseboard ( 1970's I guess) 16KW / 55,000 BTU/HR . I worked well until the circulator pump seized albeit with a heavy load on my electic bill ! I used it for my back up especially when heatpump stuggled ( 2yr old Broan ) . Nat gas wasn't in budget when i had Broan installed uggg , hindsight . Broan has been problematic but that's another argument .
I have a GE 40 gal elect hot water heater nothing fancy.
What my thoughts are is to have an old school cast iron gas boiler with domestic hot water coil . My previous home had an oil boiler with same and we always had plenty of hot water & it didn't seem expensive to run boiler in summer but never really crunched numbers ($).
I have had 4 estimates and first thing out of salesmans mouth is tankless combi . Rinnai , Navien and Laars were presented . I had to request separate estimates for cast iron boilers and only one offered a Columbia Boiler with DHW coil.
Problem i have is that the tankless , albeit nice and neat and pretty have a multitude of angry customers that have spent a lot of money on a hit or miss system .
I like the old school way for reliability but see very little info on this type all in one boiler . Maybe a stand alone gass hoy water heater next to a standard boiler might be a better option .
any thoughts most appreciated .


Comments

  • Ironman
    Ironman Member Posts: 6,868
    You want to get a BOILER with a separate indirect water heater that works off of the boiler.

    A boiler with an internal coil wastes a tremendous amount of fuel since it must constantly stay hot 24/7 year round to heat the domestic.

    Even the most basic cast iron boiler with an indirect would probably use 30% less fuel than one with an internal coil. A mod/con would probably use 50% less.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • VBdiver
    VBdiver Member Posts: 2
    Thanks Ironman & Hatterasguy for response .
    What exactly is meant by an indirect hot water heater ? Sorry i'm not up on all the nomenclature and am trying to educate myself . I think the sales folks are misinformed or steered to sell tankless units only .
    I want something simple , have had enough headaches with my 2yr old heatpump.
  • Ironman
    Ironman Member Posts: 6,868
    VBdiver said:

    Thanks Ironman & Hatterasguy for response .
    What exactly is meant by an indirect hot water heater ? Sorry i'm not up on all the nomenclature and am trying to educate myself . I think the sales folks are misinformed or steered to sell tankless units only .
    I want something simple , have had enough headaches with my 2yr old heatpump.

    You can search in any boiler manufacture's site: they all offer them. And you can mix/match any brand with any boiler brand. Triangle Tube has a tank in tank design which recovers very quickly. Any properly sized indirect/ boiler combination will also give virtually unlimited hot water.

    With this type setup, the boiler only fires when the temp in the indirect drops enough to call for heat.

    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    VBdiver
  • bmwpowere36m3
    bmwpowere36m3 Member Posts: 512

    Be a bit careful getting the cheapest units.; If they have a 3/4" coil, rather than the preferred 1" coil, the recovery time is extended dramatically. In some cases, the boiler reaches high limit and shuts down because the heat transfer is not that good.

    You can also save some money by purchasing the 35 gallon unit and storing at 160F and mixing down to 130F. This, effectively, gives you the same capability as a 50 gallon unit.

    Interesting, the Crown Megastore 50gal has 3/4" connections… that's what I installed and have heard praise from a few local pros. However, my limiting factor is a 55K BTU mod/con… not so much pumping/GPM/delta T.