Replacing an old/inefficient oil burner with...an oil burner (?) Or...?

Well… there isn't enough information there to really allow me to say. Based on the possibility of selecting the Bosch Greenstar series boilers, though, I'm going to guess that this is a hot water heating system, not steam.

And I will make a further assumption: that for some reason you MUST replace the old boiler. It's cracked, or has some other fatal defect.

Based on that, I would agree with @Ironman .

However

What's the matter with the old boiler? What's the age, make, and model? Has it been serviced recently? If so, what were the combustion results from the service and adjustments?

You quote a 60% efficiency. Bluntly, unless it is really old — like an old Snowman refitted with an old oil burner conversion from coal — it should be doing a good deal better than that.

Gut feeling: based on your two choices, the Peerless. But I agree with @Ironman about the Buderus over the Peerless. I am looking at the age of the occupants of the home and regardless of the cost to operate the Peerless has all the regular parts that every oil burner repair man can easily make work.

Assumptions:

1. You need to replace it for a legitimate reason. (not just to get a new more efficient system.)
2. You want the system to last at least 20 years (you can expect 30+ years)
3. You need something that is easy to maintain
4. The age of the occupants precludes DIY service
5. The price of the system and/or the oil is not an issue

In other circumstances, I would go with System 2000. The lower cost of operation will outshine any cast iron boiler with standard oil burner controls Also I like the Buderus Oil Fired boilers better than the Peerless 

As far as a GreenStar, I like them also, however there are parts and systems on the boiler that require special knowledge, parts and training to get the maintenance and some repairs completed properly.  The life expectancy may be less than 20 years putting the possibility of a replacement being needed during the time frame of your occupancy.   And at a time when you are much older and less able to deal with that situation. 

are you sure this winter was mild? In much of the US, it was much colder than average. How many gallons have you used the past few years?

Also, where do you live, and how many sq ft is your house?

For comparison, I maintain our 4-unit condo building in the Boston area, 4800 sq ft total, built circa 1930. And we burn about 1200 gallons per year, which this season is costing us about $4200 at $3.50/gal average.

We have a separate water heater, while your hot water comes from oil, so for an apples-to-apples comparison, I'll add $800 to our oil cost, if we were making hot water from oil.

So for an apples-to-apples comparison, we'd be spending about $5000 in oil to heat our entire 4800 sq ft condo building, plus hot water, in the Boston area. Our envelope heat loss is about 15 BTU/hr/sq ft on a zero-degree design day, which is good for an old house in this area.

So if you live in a similar climate in a much smaller house, your biggest problem may be your leaky house envelope itself, and not an old boiler.

Well that gets me a little farther along.

First, switching from oil to LP will cost you money, no matter what boiler you put it, unless you are somewhere in the upper midwest where theye is enough agriculture to keep LP costs down.

Second, you have a wonderful salesman somewhere. There shouldn't be anything wrong with that Crown boiler that a good technician can't fix. Further, it should be achieving at least 80%, not 60%, if a good technician is doing the adjusting. What that translates to, getting down to the dollars here, is that even putting in the whizziest new boiler, all singing, all dancing, and costing a good bit to maintain (the EK, the Navien, for example) might save you as much as a few hundred dollars a year — and that means it will take a decade or two to pay for the new boiler and installation in terms of fuel savings.

Oh and I agree — this was not a mild winter, at least in the northeast.

With high heating costs and\or comfort issues I like to start with the question: how much “pain” does it cause you?

$5,000 to heat your home for a single winter would be very painful for most of the folks I work for, and it’s painful to hear that you’re having to spend as much to heat your home.

In my own home, the combination of “going to be here for a long time” and a lot of pain from high energy bills led to a willingness to spend a lot of money to both dramatically increase our comfort and reduce home energy costs.

Big picture: I’d find the best guy\gal in my area for the job, and I’d buy the best piece of equipment he is recommending for the job.

If I were in your shoes right now: I would line up the site visit with the heating contractor. Before the site visit, I would determine where I could seal up and insulate cost-effectively, and then I would have the contractor size the equipment to the new load. I would run the numbers, based on the contractor’s chosen equipment, and decide whether a new boiler makes sense on the numbers alone.

If a new boiler did not make sense on the numbers alone, then I would look at how the air sealing and insulation measures stacked up on paper.

My bet is that your best path is to spend a chunk on air sealing and insulation measures, and another chunk on a mid-efficiency boiler that will reliably make it to the 20-year mark.

FYI: The average job I take on significantly addresses envelope issues as a path to cost-effective heating solutions to high home energy costs.

I have a Peerless WBV-03 and it's a ok boiler but it's not even comparable to the EK System 2000. I wouldn't install anything else in my home if I had to replace my boiler. I work on dozens of both boilers and the homeowners who have the EK are always much happier with the energy efficiency of the EK.

The EK isn't really any more complicated than other boilers. When they are installed and setup properly the annual maintenance is a lot easier than other boilers. If you ever have any issues you won't find better customer service and technical support than what EK provides.

I also feel like a Navien would be something to avoid like the plague.

Though I prefer Buderus boiler I must say the fact that EK folks will respond here on this sight is a big comfort. The Peerless is unfortunately an antique.

I don't scoff at pin boilers. May do scoff at them and continue to install then. They usually last and 82% efficiency is not bad and they are for the lower priced market.

If you had to sell your house and the new owner wanted a new boiler and you agreed to make a deal with them where you put one in at cost to get the sale are you still going EK? Doubt it.

The problem with installing a pin type boiler like a WBV, WGO or Burnham V8 is why would you when you can get a 3 pass Pure Pro Trio or Utica Tri Fire for pretty much the same cost?

If buying the least expensive boiler is the deciding factor a pin type Crown boiler is probably going to be less expensive than the WBV, WGO or V8.

@HVACNUT can you even get a dry base steel boiler anymore? I work on a bunch of them but it seems like they are all at least 20 years old. Builders loved them because they were the least expensive option.

@jesmed1 said-

"I had looked at the Buderus and Biasi B10 3-pass boilers as possible replacements when our WGO's wear out. But I hadn't heard of the Pure Pro Trio or the Utica Tri Fire, so thanks for mentioning those. Either one could be a good option for us.

The Biasi B10 is no longer sold here, but the cutaway schematic of the Trio sections looks a lot like the Biasi sections. And the Trio website says the Trio is "assembled in PA" with a warranty from Boyertown Furnace Co. So I wonder if they're buying the B10 castings from Biasi and making Trios from them."

Correct. Boyertown Furnace also sells these as the Solaia. They're nice boilers, and you can fire them with oil or gas.

And for those who really, seriously need a coil, there's now a 3-pass with a coil called the Solaia Forte:

https://s3.amazonaws.com/cdn.columbiaheating.com/residential-boilers/solaia-forte/1%20Solaia%20forte%20literature.pdf

And don't forget the Energy Kinetics boilers.

@Jim_M that's quite a big difference. My indirect water heater accounts for a small percentage of my oil use. How has the electric water heater affected your electric bill? You must use a lot of hot water.

Columbia Emerald series is a steel fire tube boiler that sits on top of a combustion chamber.