help me pick properly sized boiler
A month ago i discovered a small leak in above-water section of my 8-year boiler. (Water feeder added 50 gallons of water in 1 month!). I'll survive this winter but i'm slowly getting ready to replace the boiler.
I measured my radiators and living spaces. Using Weil-Mclain's measuring PDF it seems I'm experiencing heat lost of around 81,000 BTU while my heating radiators output 78,500 BTU (327 Sq Ft of heating space).
Q1. Based on the drawing below, is my math correct?
If so, it seems i only need to install a smaller of the boilers offered by the manufacturers. My current one is Burnham (pic below) that seems way oversized based on the math.
Q2. Am I correct to assume that I only need a boiler outputting only around 85,000 BTU +, am i correct with this assumption?
Q3. Of all the boilers on the market, which one would you suggest (steam heat and oil as fuel)… Burnham, New Yorker, Weil-Mclain… Any others?
Comments
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You have steam heat. Steam is sized by Equivalent Direct Radiation (EDR), not BTUs. As you already counted sections, you need to look up the EDR .
Go to the data sheet and find the "sqft of steam" for all your rads and add them up.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
does the home heat adequately in the coldest days? If so you have enough heat emitters. No need in sizing the boiler larger than what the heat emitters can deliver
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream
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peerless or weil mclain there are a number of others that are also good if those are too expensive. go with a top outlet boiler. gravity isn't exactly in your favor in separating the steam and water in side outlets. they can work well if installed correctly buy they are less forgiving.
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@patrykrebisz , do you have natural gas available?
All Steamed Up, Inc.
Towson, MD, USA
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting0 -
Hello patrykrebisz,
Your picture cut off part of the data you need to understand. The steam boiler should be matched to the radiation (the radiators) the EDR, your present boiler may be too big, a common issue.
Also this may be a good time to correct any near boiler piping issues. Post some complete boiler pictures so the members here can critique your system.
Peerless has steam oil-fired boilers.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System0 -
To answer the questions:
yes, the system warms up good on cold days. the boiler heats up for a few minutes, then low water cut off goes in test mode. Afterwards, soon after, the boiler hits almost 2psi before shutting off (pressuretrold). Soon after it works for a few more moments then thermostat reaches the desired temperature and the system stays off for next, say, 15 minutes.
i do have access to gas but i'm not sure it would be a great savings… not to mention that i plan to do the swap myself (with help of my plumber friend0 so i would rather not have to do too much gas work.
my near boiler piping seems to look good:
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If your friend is a p;lumber, they should be able to handle the gas.
All Steamed Up, Inc.
Towson, MD, USA
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting1 -
Just match your EDR to the sq. ft. of steam rating on the boiler you are looking at. I like Peerless, but that's probably at least partially because that's the one I picked (choice-supportive bias it's called).
Your current boiler is 512 feet of steam, way too big. If you fall between two boilers, choose the smaller one.
NJ Steam Homeowner.
Free NJ and remote steam advice: https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/
See my sight glass boiler videos: https://bit.ly/3sZW1el
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Looks like your piping off the boiler feeds two mains.
It would be better if you brought the two mains down to the boiler header individually.
If your boiler is small you may get away without changing that but when installing the new boiler why chance it. It will work better.
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In the areas I've circled in red, does it say "Burnham" on everything? Couldn't see for sure on F. I think the height measurements are off. B, C, G, H should be 19" height, F should be 22" height. Is that correct? The center-to-center distance between each section (or rib as you call it) should be 1.5". I'm getting the following:
A: 1.6x24 = 38.4
B: 1.4x24 = 33.6
C: 1.4x24 = 33.6
D: 3.4x14 = 47.6
E: 3.4x6 = 20.4
F: 1.3x14 = 18.2
G: 1.4x26 = 36.4
H: 1.4x22 = 30.8
I: 3.4x8 = 27.2Total = 286.2
@delcrossv already posted a link to the sheet you need:
I'm not a pro, but I have a few other questions: Just to confirm, did you actually see the leak in the cast iron section of the boiler or are you just assuming it's there based on the water consumption?
If the leak was visible, that means your boiler failed after only 8 years (even though the manufacture date code of 11/2013 puts the age at 11+). This is unusual and would make me suspect a water quality issue. Do you have a water softener?
Lastly, please post your current gas and heating oil rates. Price/therm and price/gallon.
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A peerless 63-03 would be the closest (gas) at 308 sqft. The L at 233 would be too undersized imo. I'm not comfortable with negative pickup factors.
I'd also use both taps and go to 2.5 on the header.
@patrykrebisz Are the left and right branches of your main teed together?
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
FYI, here's a heating cost calculator where you can compare the cost of oil with natural gas per BTU, after entering the unit price of each.
Here in the Boston area, gas is now only about 10% less expensive per BTU than oil. Gas prices here went up a lot this season, and oil went down. My friend switched to gas over the summer, right before the price spike, so his timing wasn't great.
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I WOULD go with the lower EDR Boiler. Less then 1% of the run time you need 100%.
you can always tighten the envelope.1 -
I'd go with the higher number. Remember, the CycleGard low-water cutoff with its intermittent level checks means the boiler may not be making steam for up to 10 minutes out of every hour. If you cut it too close, the system won't heat well.
All Steamed Up, Inc.
Towson, MD, USA
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting1 -
The 63-03L is rated 74,000 output. They have 68,800 worth of radiation. That means the boiler produces 5,200 over that.
I'm curious if the heat loss really is 80,000+ how big this house is and what is the design temp?
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
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Go by sqft, not BTU.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
I go by btu.
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
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I'd go by sqft. The radiation is already installed. Btu would be the way to go if it were a new install.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
I'm using the btu/h of the radiation.
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
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Then doing the math should get you the same 286 sqft. Did you drop the pickup?
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
Yes I did.
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
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Ok. That's dice the customer can roll.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
I've been posting about this for literally 11 years now. How have you not seen any of my comments regarding pickup factor?
We give the OP our opinions and they decide how they want to go. Since he's installing his own boiler I'm betting he'll be fine.
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
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Sure I have. Just that without seeing the OP's house, I'm not necessarily comfortable dropping it. Who knows, could have swiss cheese windows and be perched on a windy mountaintop. Limitations of remote advice.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0 -
I do agree with that. That's why I asked about the heat loss that was mentioned.
However even if it is high the radiators will only condense so much.
We don't usually see steam systems under radiated so I'm really curious how the heat loss was done.
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
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With the boiler reaching a pressuretrol cut out at 2 PSI and my system heating just fine with 0.072 PSI or less (even below design day temp) with an undersized boiler, just going by EDR and Sq. Ft. values and fairly well insulated basement pipes. I say patrykrebisz boiler could be smaller.
My opinion, but do your own due diligence, I am very happy NOT having oil, to me oil seems very high maintenance, which is more money spent in the need of keeping warm.
National - U.S. Gas Boiler 45+ Years Old
Steam 300 SQ. FT. - EDR 347
One Pipe System
2 -
Even the 03 is almost half the size of what's in there now.
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.0
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