Looking at new boilers

Hap_Hazzard

My Peerless G-561 is working fine, but since it's close to 40 years old, I thought I'd start looking at potential replacements and making plans, because bad things have a way of happening when you're least prepared.

My first preference would be to replace the old Peerless with a new Peerless. When you have a boiler that lasts 40 years—and who knows how many more by the time it finally fails—you don't really need to switch brands. Also, the layout is very similar, so I can keep my near boiler piping, with only minor changes. I might want to upsize the risers to take advantage of the bigger tappings, but that's about all I'd change.

I'm looking at the Peerless 63 series, and the model that matches my radiation (394 ft²) the closest, without being under, is the 63-04, which is about 16% oversized, but the next one down, the 63-04L, is about 3% undersized.

model     output     % oversize
63-04L   383 ft.²     -2.91%
63-04     458 ft.²     16.10%

So is it better to be a little undersized or a little more oversized?

One advantage to this situation is that you can convert a 63-04 to an L by removing one burner and changing three parts:
Part # 50303    Burner Tray Rear Support – 63-04L
Part # 50267    Gas Manifold – 63-04L
Part # 50284    Flue Collector – 63-04L
All other parts are the same in both models, and of course you can also go the other way too.

I can't help but notice that SupplyHouse.com doesn't have either one of these in stock. The 63-04 is on backorder until March at the earliest, while 63-04L is just out of stock. I'm assuming this has something to do with those "supply chain issues" we keep hearing about, but I don't know if dealers can't get the boiler or if PB Heat, LLC, can't get the components it needs to build packaged boilers, but, either way, they probably wouldn't let me drive up to their factory—only about 24 miles from my door—and pick one up anyway.

My second choice, in case I can't get a Peerless when I need one, would be the new SteamMax, from U.S. Boiler. I've heard some good things about this model, and it looks good in the literature, but, unfortunately, that's all I have to go on for now. SupplyHouse.com doesn't even show it as "out of stock." They don't even mention it. I don't know anyone who's installed one or had one installed, and U.S. Boiler doesn't say anything about when it will be available.

The design is supposed to address the corrosion problems of the Independence line. It remains to be seen, however, if they succeeded.

Choosing a SteamMax model presents the same problem as the Peerless 63 series.
model         output     % oversize
STMX150    388 ft.²    -1.65%
STMX175    450 ft.²    14.07%

The 150 is not as undersized as the 63-04L, but there is no upsize path from the 150 to the 175. The 175 has five sections; the 150, only four. So if I'm not happy with the 150's output, I'm stuck with it.

I've also looked at the MegaSteam, of course. Being the most efficient residential steam boiler on the market, with the best warranty in the industry, you'd think it'd be a shoo-in, but, unfortunately, the only way I could get that boiler with that warranty would be to switch from natural gas to oil, and there are about a million reasons why I'd never do that, not the least being that, despite the vaunted efficiency, my TCO would be higher! I'd have to be crazy to do that.

We all know that the MegaSteam works great with a gas burner, but the price you have to pay to use the most economical and ecologically responsible fuel source is to give up that industry-leading warranty—on a brand new boiler! In the unlikely event you get one with a casting defect in one of the sections or any other defect, you are SOL. Even under the best circumstances, I'm a little reluctant to go from a quiet atmospheric boiler to one with a power burner to gain 3.6 % AFUE, but it just seems crazy to me that U.S. Boiler won't support this boiler for use with natural gas. In fact, while they might think I'm being a little unreasonable, it leaves such a bad impression that I'm not inclined to take it on faith that the new SteamMax will live up to their claims. I'll need to wait for data.

EBEBRATT-Ed

Go with the smaller Peerless because:

Your radiation is probably oversized for the house anyhow
If you sized the boiler based on square foot that already includes the 1.33 piping and pick up factor which easily covers your 3% under. Your so close I wouldn't give it a second thought.

The 63 has been around a while and seem pretty robust

I don't know the Steammax but I don't like anything Burnham that's just me. I have seen too many leakers even on their hot water boilers

Hap_Hazzard

The radiation is just about right. The house was built in 1940. Fiberglass insulation was apparently still too beta for the builders.

My G-561 is rated at 405 ft.², and it seems barely adequate at times. I'm sure it's not as efficient as it once was, but the same thing will happen over time to whatever I replace it with. I'd kinda like to start out with a little extra.

ethicalpaul

3% undersized is a perfect size. The whatever percent pickup factor is grossly oversized itself.

cross_skier

I also started shopping as my Peerless 61-05 is 23 years old.  Good to hear your G-561 is 40 years old, mine might have a few years left.  Wish I knew!

The 63-04 is also on my list.  I really like the 3" outlets.  The 2-1/2" inlet is big enough for wanding and there is even enough room for a wet dry sludge vac.  Also it's a Peerless and they have earned my trust.

I also like the Megasteam.  Hoping that someone comes out with a gas high-low burner that would work with it.

New England Steam Works avoids all Burnham except the Megasteam for what it's worth.

Good luck with your decision

Hap_Hazzard

ethicalpaul said:

3% undersized is a perfect size. The whatever percent pickup factor is grossly oversized itself.

🤔 Hmmm. Well, the 63-04L is about $420 cheaper (according to SupplyHouse), and it's not on backorder—not that I'll be ordering one in the foreseeable. Mebbe I should price the upsize conversion.

ethicalpaul

You can price it, but you won't need it. It's nice to have the option though in case you put an addition on your house

Get prices from your local supply houses too. @clammy gave me a recommendation to try a local place here in north jersey and they delivered that same day for free at a very competitive price, and they were friendly to homeowners even!!

Also I would urge you to go ahead and get it whenever you feel like it and can afford it. It's a great summer/autumn project.

Hap_Hazzard

cross_skier said:

The 2-1/2" inlet is big enough for wanding and there is even enough room for a wet dry sludge vac.

I haven't tried it yet, but I think you can wand your 61-05 if you take off the tankless coil flange. I've thought about going in there with a pressure washer.

Hap_Hazzard

ethicalpaul said:

You can price it, but you won't need it. It's nice to have the option though in case you put an addition on your house

Or maybe a sauna. 🤔

ethicalpaul said:

Get prices from your local supply houses too. @clammy gave me a recommendation to try a local place here in north jersey and they delivered that same day for free at a very competitive price, and they were friendly to homeowners even!!

Also I would urge you to go ahead and get it whenever you feel like it and can afford it. It's a great summer/autumn project.

I've been assuming I'd hire a pro to do the installation and let him make the profit on the boiler, if it works that way. I'd forgotten that you did yours yourself. Does Peerless still honor the warranty if you install it yourself?

ethicalpaul

Nope! Yeah if you are having it installed the installer will want to buy it probably. I was erroneously thinking you'd install yours.

Hap_Hazzard

ethicalpaul said:

Nope! Yeah if you are having it installed the installer will want to buy it probably. I was erroneously thinking you'd install yours.

It's not that I don't think I can do it. I'm just worried about voiding the warranty. Is that a real concern or not?

cross_skier

I installed mine and did a pressure check of the block for leaks before moving it to the basement. 

Nothing like dollying a 500lb block downstairs to make you feel like a man

Hap_Hazzard

cross_skier said:

Nothing like dollying a 500lb block downstairs to make you feel like a man

I'd probably use a come-along, like the one I used to move a piano up a fire escape to a second-floor auditorium.

I got war stories.

dopey27177

Being over sized by 16% will not effect your fuel bill all that much.

Last year I had that discussion with my son.
He did not listen to me because he told me I am old school and do not understand that a little under sized is o.k.

He saved three hundred dollars on the cost of the boiler.

He lives in the mountains of Pennsylvania. Last heating season he had seven days in a row of temperatures under 10 degrees Fahrenheit. His house was heated to 62 degrees.

The boiler could not keep up with the continued low outdoor temperatures, fortunately he had a fire place in the living room, 1/2 cord of wood and a couple of small fans.

I generally do not make a point over, over sized boilers because there is so much stupidity over how much a boiler be over sized.

Any contractor that does not know how to size a boiler should not be in the business. I believe in this saying "let the customer beware."

Unfortunately this site exists because people are or get into trouble because they look for the cheapest contractor not a contractor with a reputation of doing good work.

Most drastically over sized boilers can be down sized by lowering the fuel input.

More importantly the over sized boiler in most cases will not affect the efficiency of a heating system provided that system if steam is vented properly, pipe insulated properly and no back pitched piping and the boiler is or was installed properly.

Jake

Hap_Hazzard

Now this is interesting. Based on the prices at SupplyHouse.com, the parts required to convert a 63-04L to a 63-04 cost about half of the price difference between the two models, so if you want a 63-04, you can save about $210 by buying a 63-04L and converting it, and you'll still have the parts to back-convert it if you change your mind. 😎

KC_Jones

Hap_Hazzard said:

Now this is interesting. Based on the prices at SupplyHouse.com, the parts required to convert a 63-04L to a 63-04 cost about half of the price difference between the two models, so if you want a 63-04, you can save about $210 by buying a 63-04L and converting it, and you'll still have the parts to back-convert it if you change your mind. 😎

You're sounding a bit like @ChrisJ and his downsized Weil Mclain. Do both boilers use the same draft hood? On the Weil the draft hood changes for the smaller burner to the larger burner on the same size block.

Knowing what I know now, I'd go with the smaller one. You aren't really 3% undersized IMHO. You are going from a 33% pickup to a 29% pick up. With the larger boiler you will have a 54% pick up factor. This seems like an easy decision to me.

Hap_Hazzard

KC_Jones said:

You're sounding a bit like @ChrisJ

Hey! Watch it there.

KC_Jones said:

Do both boilers use the same draft hood?

Same draft hood, different flue collector. That's the most expensive part that has to change. It's about $100.

KC_Jones said:

Knowing what I know now, I'd go with the smaller one. You aren't really 3% undersized IMHO. You are going from a 33% pickup to a 29% pick up. With the larger boiler you will have a 54% pick up factor. This seems like an easy decision to me.

Why would the pickup factor be that much higher? They both use the same sections, same amount of water. Isn't that what determines the pickup factor?

KC_Jones

Pick up factor is based on burner output to system size. If we apply your system EDR to those boilers, that is the pickup factor you end up with.

cross_skier

I would get the larger 63-04 and a two-stage valve.  Kind of fancy but it will protect you from -10F weather and save money by greatly reducing short cycling.

Here is the valve others have reported success with -- https://www.supplyhouse.com/Robertshaw-700-053-3-4-x-3-4-Two-Stage-Natural-Gas-Valve-300-000-BTU

EBEBRATT-Ed

@Hap_Hazzard

IMHO oversizing is foolish. As I mentioned above with steam you size the boiler to the radiation not the building heat loss. Your radiation is most likely way oversized for your house.

Why not do a heat loss of your house as a back up check? Compare your house heat loss to the radiation output.

Once you get the answer to that you will pick the smaller boiler

KC_Jones

cross_skier said:

I would get the larger 63-04 and a two-stage valve.  Kind of fancy but it will protect you from -10F weather and save money by greatly reducing short cycling.

Here is the valve others have reported success with -- https://www.supplyhouse.com/Robertshaw-700-053-3-4-x-3-4-Two-Stage-Natural-Gas-Valve-300-000-BTU

The max output of the system is 94,560 BTU based on the EDR calculation.  Exactly how will the bigger boiler “protect you from -10F weather”?

The limit of any system is the radiation, putting in a bigger boiler can’t increase the systems ability to heat the building.

As far as pickup factor, the smaller boiler will have enough output to heat ~183’ of 2” uninsulated main, at the same time as all his radiation.  I doubt that’s the situation, but is presented to illustrate how much excess is usually designed into these systems and why it’s important to not oversize.

Ultimately it’s the OP’s decision, but I do know how I’d handle it in my house.

Hap_Hazzard

EBEBRATT-Ed said:

Your radiation is most likely way oversized for your house.

I don't know why you keep saying that. What's that based on? You've never seen my house. I've lived in it for 22 years.

EBEBRATT-Ed said:

Why not do a heat loss of your house as a back up check? Compare your house heat loss to the radiation output.

As my research methods professor used to say, don't evaluate it if it's not up for grabs. I'm not going to be buying more radiators. I already added two new ones this summer. I'm done with that.

cross_skier

  KC_Jones said:

cross_skier said:

I would get the larger 63-04 and a two-stage valve.  Kind of fancy but it will protect you from -10F weather and save money by greatly reducing short cycling.

Here is the valve others have reported success with -- https://www.supplyhouse.com/Robertshaw-700-053-3-4-x-3-4-Two-Stage-Natural-Gas-Valve-300-000-BTU

The max output of the system is 94,560 BTU based on the EDR calculation.  Exactly how will the bigger boiler “protect you from -10F weather”?

The limit of any system is the radiation, putting in a bigger boiler can’t increase the systems ability to heat the building.

As far as pickup factor, the smaller boiler will have enough output to heat ~183’ of 2” uninsulated main, at the same time as all his radiation.  I doubt that’s the situation, but is presented to illustrate how much excess is usually designed into these systems and why it’s important to not oversize.

Ultimately it’s the OP’s decision, but I do know how I’d handle it in my house.

Hi,
Your answer is fine in a perfect world where the radiation is sized for the coldest day of the year, say -10F.

Based on experience the radiation will likely be insufficient on the coldest day of the year and the boiler will short cycle on pressure.  The two stage gas valve will save you a lot of money by reducing/eliminating the short cycling.

Also based on experience boiler manufacturers tend to overfire and stress the metal to get more out of a smaller boiler.  Downfiring is usually possible and should extend the life of the boiler.

In my house slightly oversized is good.  Admittedly I did not examine the EDR figures as closely as I should have

Hap_Hazzard

I calculated my EDR based on the columns, sections, make & model of each radiator, but I know some of them aren't living up to their full potential, like the two radiators in the master bedroom. Their combined EDR is 65 ft², but they're fed by a single 1" riser from the main. The biggest radiator you can feed with a 1" riser is supposed to be 24 ft². Anything over 60 ft² should be on a 1½" riser. Technically, both radiators are too big for a 1" riser, but they're sharing one. In fact, all six upstairs radiators are on 1" risers, and four of them are too big for one, and one of the ones that's actually less than 24 ft² has a 4' runout from the main, emerges from the basement at the foot of the wall at the top of the stairway, takes a 45° ell into the wall, goes upstairs and comes out of the wall under the bathroom floor, runs out about 6' to a 90° ell, runs another 6' to the other wall where it finally meets another ell to the radiator valve. Nevertheless, the radiator actually heats pretty well. So does the 12' of pipe under the floor that didn't figure in my total EDR, but it probably should. Most of the risers just run straight up through uninsulated outside walls. As my father used to say whenever I didn't close a door fast enough, we're heating the outdoors.

EBEBRATT-Ed

@Hap_Hazzard

I think your missing the point

Most everyone knows that all the old steam systems are over radiated for the heat loss of the building....that's just a known fact.

If you do a heat loss of your house as I suggested you will find out if this is true in your case or not

As @KC_Jones mentioned putting a larger boiler in that provides more steam than the radiators can possibly condense will not heat the house up any quicker.

Built in to the boilers net rating is a 33% yes, 33% pick up factor over and above what the radiation can condense

But, if you want the larger boiler go for it

And where did I suggest buying more radiators?

cross_skier

I did downsize 6 radiators -- entry, parlor, master bedroom, back bedroom, upstairs landing, and dining room. I had an opportunity to do it for free when a large house in the neighborhood was split into condos.

My current edr is 400 which matches to the 61-05 sq feet of steam.  I am probably slightly oversized as my actual pickup factor < .33 ( insulated mains and returns)

My radiators are too small for -10F days but are really comfortable for 95% of the winter.  I am thinking lo-high gas valve may be the fix for short cycling on really cold days if combustion is ok for both settings.  It usually takes about 3 hours of continuous firing before the boiler cycles on pressure.

The Steam Whisperer

On other thing to keep in mind when sizing a steam boiler is the type of Low Water cut off. The Peerless, like most other manufacturers, has a Hydrolevel Cycle Guard, which reduces the boiler capacity about 7% for the 63/64 due to the regular test cycles ( this percentage will vary depending on the control model and boiler wiring for other boiler models). This reduced capacity is not reflected in the ratings. However, if sizing by radiation, that is within the 33% pick up factor so its not a problem. However, if you have a steam system that your are designing to heat loss, it can quickly become a problem.

Regarding oversized radiation.... in Chicago, if the building was built during or after WW1 the radiation is usually about 60% oversized. But prior to that, it is often right on the money or very close unless thermal upgrades have been made. These older buildings only need small boiler. I heated 5 of 6 units in a typical chicago six flat with a 345,000 input Peerless 64-07. The system had 2x 3 inch mains that were 3 inch the full length, so lots of pick up load. The building also ended up with a fully exposed side, which it did not have for at least a very long time, due to a neighboring teardown and new home built.

Hap_Hazzard

@EBEBRATT-Ed

A known fact, is it? How old are we talking? 100 years ago? 200? I think your view of history is lacking in detail. It is a known fact that they overdid the radiation in the roaring 20s, partly in response to the 1918 influenza epidemic, but the roaring 20s stopped roaring, and during the great depression they didn't overdo anything. Then the war came along and you couldn't get steel or cast iron to save your life. Look at what toys were made of before the depression and after WWII. You just don't see any cast iron toys after the 20s because it became first unaffordable and then a strategic resource. So how do you think that might have affected how much people could afford to spend on radiators?

My house was built in 1940. Originally it was about 1200 ft² and had 7 American ARCO radiators totalling 274 ft² of steam. In the 60s, they increased the square footage by 50% and added 2 Burnham radiators, worth another 51 ft²; a 2' fin-tube convector, worth about 11 ft²; and a big 9' fin-tube unit that never worked as it was piped with 1" copper. So it may have started out with adequate radiation, being built between the depression and war years, but when they increased the square footage by 50%, adding an entry door, a patio door, a large bay window and several other windows in the bargain, they increased the radiation by about 23%. I've replaced the convector that didn't work with a 47 ft² EDR radiator and put a 12 ft² EDR radiator in a room that didn't have one, so now it's just about right again.

The reason I said I'm not buying more radiators is that you suggested doing a heat-loss calculation. You normally do that when you're trying to figure out how much radiation you need. I already have all the radiation I need, so what's the point? Besides, any estimate of heat-loss would be time-consuming, because of things like the bay window, and largely based on guesswork, because the amount of insulation in any given wall is unknown, as is the number of risers that might have asbestos. It could be as many as all of them or as few as none of them. I'm not about to tear open my walls to make a more accurate calculation that only tells me what I already know: the amount of radiation is just about right.