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Oil burner size

Chris_H Member Posts: 3
Hi All,

  I got a couple of estimates to replace my 30 year old oil burner and storage tank with a new Indirect tank and a new Peerless boiler, however, there is a problem. The two estimates are for two different sized boilers and I am not sure which size is the right size.

The currently installed boiler is an old Burnhan RS112, I believe it is labelled as 123MBH. One company gave me an estimate with the Peerless WBV-04 and the other said that was "too big" for my house and they would use the Peerless WBV-03.

The house is a cadillac-split, which is a split level ranch with an extra set of rooms over the living room. The house was built in 1955 and is approximately 1700 sq ft with two heating zones, one for the basement and one zone for the rest of the house. It has 4 bedrooms and 3 bathrooms.

We don't use a lot of oil because it is just my wife and I in the house, so I don't want to use our oil consumption as a metric.  Any help would be appreciated.


  • earl burnermann
    earl burnermann Member Posts: 126
    New Boiler

    You really should have a heat loss calculation done to decide on what size boiler you need. It's an extra expense that saves you money every day. The indirect is a great idea though. Can really reduce your standby loss. Especially if you have an on-demand heating system.

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  • Robert O'Brien
    Robert O'Brien Member Posts: 3,541

    I can guarantee the heat loss is nowhere near either of those,do the calculation and find out. I'd go with a triple pass/indirect/odr over a pin boiler,it will pay for itself many times over. More than likely the smallest boiler will still be too big! This is a 3 section Buderus in a 2500 sq/ft house.
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  • Chris_H
    Chris_H Member Posts: 3
    edited August 2012
    Heat Loss

    The old boiler has

    struggled in the past to maintain temperature on the really cold days that are common in NY. So, I am leery about getting something too small. The garage is integrated into the house so the  floor above it is very susceptible to the cold. The house is not particularly well insulated so the boiler does have to work.

    One room doesn't have a long enough baseboard in it so that will put a bigger load on the boiler. I am going to try to get an energy audit done, maybe I should just wait until that is complete.

    I find a web site that has a heat loss calculator which looked interesting. I may give it a go over the weekend and see if I can get a number. Playing with it so far and the numbers are starting to climb. I didn't see a spot in the calculator to account for the hot water needs of the house so, I am not sure how that affects the boiler requirements

    Keep the comments coming...
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    Boiler size

    I would bet it is not the boiler size that is the problem but the way it is firing.  It may only be delivering 50% of its capability.  The boiler not only has to be sized properly but it has to operate properly.  Oil boilers are mis-fired quite often because it makes them look efficient when in reality they are operating 20%- 30% below their ratings.
  • Paul48
    Paul48 Member Posts: 4,469

    Is there a lot of scorching on the face of the boiler?
  • Ron Jr._3
    Ron Jr._3 Member Posts: 603
    edited August 2012
    Peerless WBV3

    I have one in my house . 1500 sq ft . Worst case heatloss for my home was 50,000 btus . In actuality its probably around 30,000 .

    Just by adding an indirect and lowering the nozzle size I wound up saving 30% in fuel use . For the past 4 or 5 years I've had the system on full outdoor reset mode for winter and have had no problems whatsoever . Average 500 to 600 gallons burned a year . ALOT of hot water use and thermostats are set way too high for my tastes !  Like Bob said , the smallest oil boiler will still be way too big for a house your size . What kind of heat do you have in the home ?

    BTW , the notion that a triple pass boiler will pay for itself faster than the WBV3 is very much debatable , in my humble opinion .
  • Chris_H
    Chris_H Member Posts: 3
    edited August 2012

    As for scorching on the front of the boiler, I wouldn't know what excessive scorching would look like. The boiler was installed in '82 by the one of the prior owners so I know it is about 30 years old. I could probably take a picture tonight.

    The heat is hot water with a mix of recessed radiator and baseboard. The baseboard is  in the dining room, 1 bedroom, basement and 2 of the bathrooms. The LR has a big recessed radiator.  The kitchen uses a kick plate blower.  The den, which is on the slab, has a big recessed radiator, 2 BR have a single recessed radiator and the master bedroom has 2 recessed radiators and one other bathroom has a small recessed radiator.

    Heat in master bedroom is sufficient. The room next to the master bedroom has insufficient heating (determined that base board was not long enough). Bedroom over garage is generally cold in the winter.

    I will play with the heat loss calculator over the weekend, but initial heat loss numbers were over 80,000 but that was rough numbers on room areas.
  • R Mannino
    R Mannino Member Posts: 440
    The Cold Bedroom

    over the garage probably has nothing to do with the boiler. Get the garage ceiling sprayed with foam, problem solved.

    Bigger boilers are like hot rod engines and boy do I love horsepower, but with these crappy little tires (insufficient baseboard and radiators) all I do is make smoke and never get anywhere. So I have this great engine, but no way to put the horsepower to the ground. Sometimes the money is better spent on tires.
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