Oil Boiler Options - Crown vs. Buderus

Josh M.

Take it from an old boy who stays current.

GCM

Oil Boiler Options - Crown vs. Buderus

We have decided to replace our busted oil hot air furnace (134K output Dornback with golf ball sized hole in heat exchanger) with an oil boiler and air handler to provide us with the flexibility to replace our other 30yr old Rheem (112K output) with just the cost of adding an air handler and to also provide us with flexibility of indirect hot water, pool and spa heating (no pool yet, but want the option) and heating other areas (garage, which may be converted to living space and potentially new unattached garage). Manual J says our house alone is 165,000 BTU/Hr.

We are somewhat constrained by the size of the place where the boiler will go (a stoop space), and most notably by the height of the flue entry into the chimney (44 inches entry point to center of 8 inch flue pipe). Therefore a lot of boilers made by quality companies are exluded either based on flue exit height (most notably, Burnham, Peerless, Weil McLain). Most are top venting and only make smaller models with rear venting.

We have narrowed the options to a Buderus G215-6 (256K output) or a Crown CT7 (243K output). We are in the process of getting quotes for these. The Buderus is a relatively high mass boiler (20+ gallons). The Crown is relatively low mass (9.5 gallons). Both have three pass technology with wet mass cast iron bases. I have also been advised to get the Magic Aire air handlers.

Initially, this boiler will be connected to one air handler to heat the upstairs zone. Manual J says our upstairs requires 111K BTU/Hr, so the boiler will be way oversized at first. Our downstairs requires 55K BTU/Hr.


A couple of questions:

What boiler do you recommend for this application, or am I likely to get similar performance with either a Buderus or Crown. We are likely to own this home for a long time (30+ years). There will likely be a difference in price - is this reflective of quality?

Is it a problem that the boiler will be way oversized at first? The total mass of water in the system, especially using the crown will be quite small (only 9.5 gallons in boiler plus what is in the piping and air handler). Once we have a pool or spa and when the indirect water heater is hooked up (and the garage, etc.) the boiler will be properly sized. But those projects are somewhat in the future.

Will it be more efficient to replace both furnaces now and buy two air handlers (even though there is some useful life in the still functioning oil furnace?

Does it make sense to get a control panel (ex. Buderus Logamatic) that adjusts the temperature of the boiler water if we are solely using hydro air heat distribution?

Both models come with Beckett or Riello burners. I have been told that the parts kit for a Riello is as expensive as a Beckett. Is the cost/benefit in favor of the Riello or the Beckett?

Thank you so much for all of your help.

GCM

bruce pirger

I'm not a professional by any means...but I see you have no responses, so let me start. Often the folks here I think shy away from "long" threads of many questions...I know...I have posted too many myself!

For starters, have you done a heating load calculation? A 250K boiler is huge...maybe your house is that big/drafty...but it is huge. You mentioned Manual J, maybe this is your source for a heat load calculation?

If you put a 100K load on a 250K boiler, your boiler will be severely oversized. This is not good, very inefficient and leads to quick boiler demise.

A typical 2000 sq ft recently insulated home will run about 50-70K BTU/hr....as a reference.

Now, I am also consider the Crown vs. Buderus decision as well. Without a doubt, there more technolgy in the Buderus...in design. I have heard great things about Crown. If installed properly in a properly designed system, both should be happy for years.

System contols are key...outdoor reset, boiler return limit, etc.

Hope this provides a place to start.

GCM

Thx for Reply

Yeah, I did a detailed manual J - House is very large much of which with 23 foot cathedral ceilings. Lots and lots of windows. Also very exposed (which my Manual J program doesn't take into account).

You say that a 100k load on a 250K boiler will be severly undersized - but what is the problem? How is this different than installing a correctly sized boiler and having a very mild winter (or for that matter, what happens in the summer when the boiler is only used for hot water?

Thx for the help!

Tom M.

Weil-McLain WGO

has a flue outlet height of 29 1/2" up to 257 MBH output if that's why you disqualified it.

bruce pirger

Hello:

Again, I'm no expert, and perhaps others will chime in....If the boiler is oversized, it will short cycle constantly, i.e. it fires for only a few minutes, where a few in this case might be like two or so. This is just tough on the boiler...and a boiler burns more efficiently the longer it burns in a cycle. For an oil burner, this could mean a really short lifetime...probably not quite so bad with gas, but still not good.

To some extent, this does happen when you heat only hot water in the summer....although hot water is a fairly large load (depends on your tank size and plumbing, but sounds like you have a larger tank). With outdoor reset, the boiler operating temperature will vary with the outdoor temperature...so this helps in mild weather. If you had no reset, I believe you are right, the boiler is just oversized for the moment and you accept the inefficiency.

The best of all is modulating boilers, which can burn at different rates, depending on the load. So this might be the way to go, or at least look into, for your system.

Also, you might consider installing two smaller boilers instead of one larger boiler. In fact, I think that might be the ideal solution for your system requirements, EXCEPT you say you have limited space!

Hmmm...hope the real pro's pick up this thread. If they don't, I can only suggest posting again with a more succint post and title. These guys are great here....maybe mention modulating boiler or dual boiler in the topic, it'll get 'em going!

Josh M.

First I think that Crown is one of the worst boilers you can buy (lower than dirt). I have replaced way to many of them. You should see the earth sized crack in the oil Crown boiler I just junked! Only 7 years old. Buderas on the other hand is my baby. Take it from me I have installed hundreds of boilers. Buderas has been very faithful. I haven't junked one under 30 years old yet!

We can give you all of the advice in the world but if you are planning on putting a boiler that is 212k when your over all heating load is only 160k you are going to short cycle your boiler drastically until you get that pool and spa. At that point there is no reason to have a hydronic air handler. You are just throwing money out the window. Replace your furnace and get a 75,000 BTUH/hr boiler for your pool later. But as most homeowners you are probly going to do it your way anyhow the logomatic outdoor reset control isn't going to help much because your furnace is going to be on off control anyway and people with forced air like to feel heat from their register not 75 degree air at a constant pace.

Lee Ensminger

CT boiler


I do not know as to what Mr. Mitchell basis his opinion on regarding the CT boiler. We feel that it is a quality boiler it will serve you well.

If you are considering purchasing one for your home and have any questions. Please feel free to Contact crown Boiler we would be happy to answer them.

We can be reached by phone at (215) 535-8900 or email at sales@crownboiler.com

Sincerely,
Lee Ensminger
Crown Boiler

You may ask for Sid Feldman or myself.

Steve Eayrs

I like Buderus but

the boiler is only as good as the whole system put together. If you are oversizing, no outdoor reset controls, don't pipe it right, wrong pumps, and misc. other, than you could end up with a system that sucks more fuel than needed, is loud (burner and pump noise), and won't heat your house evenly.
In other words you may end up hating it.
On the other hand if done right, you will love it, (with either boiler).

I am sure their are some doing great jobs with Crown and other boilers, but in my opinion you can't compare it with a Buderus, anymore than you can compare scorched air and radiant heated floors. Would you rather have the Lexus or the Impala?

Steve

Eric J. Dolan

crown vs. buderus

I have installed both crown and buderus boilers in strictly hot water, and radiant applications. Size for size, there was not much of a difference in price. The buderus tends to run a couple hundred bucks more than the crown. As for Mr. Mitchells comment about the cracking problem, maybe thermal shock,control problem,and not the boiler manufacturer? I have always found that a good rule of thumb is to find out what the guy that is going to do the installation has in HIS home, and is he happy with it? When I had to replace my boiler two years ago, I chose a crown ct-3. This was based strictly on price. The buderus does however have a high silicon content casting, which makes it better able to withstand thermal shock. It all comes down to controls, piping, and a quality installation. As for the reset and boiler controls, the buderus ecomatic is a nice piece, but tekmar has better controls that do more for less money.