Vintage 1909 Gravity Hot Water Heating System

TheUpNorthState88

Hello everyone,

I feel like I’m with good company here and wanted to share photos of my home’s original gravity hot water system which still works like a charm. My home is a Colonial Revival built in 1909 and located in Michigan, USA. I have a long time interest in HVAC. I always find the subject of heating and cooling a building fascinating.

I fell in love with this home on the walkthrough, especially when I saw the cast iron radiators and the old boiler. The inspection report came back decent and no issues found with the heating system. At the time I had no idea about “Gravity Systems” but watching Dan’s videos on the HH YouTube and reading books I found on archive.org (including Dan's), I became versed on the topic. I LOVE THIS SYSTEM and the simplicity of it all.

I am just amazed at the engineering the old timers put into designing and installing these systems. And here we are 115 years later and this system works without fail in my home. No pumps, pure physics. I have recently spent time repainting all the components of the system to give them a nice fresh update. 

I have all my original cleaning tools for my boiler and I clean and maintain the heating plant myself. It helps I have the original sales brochure and care maintenance book issued by American Radiator Company. 😃 (I have uploaded both to archive.org)

Featured in my gravity system:

-1937 Ideal Boiler No.7 by American Radiator Company.
 *Tested in at 74% efficient
 * No CO leaks
 * No rust on cast iron sections
 * Excellent draft
 * Clean blue flame when operating
 * Flue temps 375°-400°
* No crazy expensive heating bills (home is well insulated, and programmable thermostat)

-Honeywell Heat Generator
*Works exactly how Dan explained in his video and the books out there. I’m amazed how even my home heats. Within 20 minutes of the boiler coming on I can touch every radiator and feel some warmth.

- 11 Cast Iron radiators and 1 baseboard
* Most are ornate Rococos by American Radiator Company

-Attic expansion tank
* This is also how the system gets filled with water *see pic*.

Asbestos abatement done on the pipes by previous owner. Wrapped in foam and duct tape. 

Thank you all, the posts here are so helpful. I’ve never had to post because I could find my answers in search.

Enjoy the pics! Feel free to go over to my YouTube (@theadamsestate1909 for a boiler and radiator tour)

Steamhead

Beautiful.

But the first and next-to-last radiators are not Rococos. The first one might be a "National" which was also made by American Radiator Co. You can see the four-column version here (scroll down):

https://www.heatinghelp.com/assets/documents/205.pdf

On the next-to-last one I can see some letters cast into the iron around the plug at the top but can't make it out. Maybe a close-up?

Ornate radiators like these went out of production around 1920.

The two flat-top ones are large-tube rads, which were in production from about 1925-1938 or so.

The boiler is a three-pass type which is quite efficient. During the war years, heating guys often installed baffles in the upper flueways of these boilers, so the hot flue gases would wipe the cast-iron better. Don't try this yourself, you need the proper equipment and know-how.

Is there a name on that gas burner?

TheUpNorthState88

@Steamhead “Most are ornate Rococos..”

The first one is a Standard Radiator Mfg Co out of Buffalo, NY and the other you mentioned (my dining room and favorite radiator) is Erie Radiator by the Jarecki Manufacturing Co out of Erie, PA. 

Unfortunately no name on the gas burner. But that baby purrs along nicely.

Steamhead

Aha! I've seen them before, now I know who made them. For those interested, the Standard catalog is here:

https://www.heatinghelp.com/assets/documents/Standard-Radiator.pdf

Jarecki is new to me, but there is a Google Book of their catalog:

https://books.google.com/books/about/Jarecki_Manufacturing_Co_Limited.html?id=ccWhNAAACAAJ

DanHolohan

Beautiful. Please pay attention to the mercury in the Honeywell Heat Generator. Thanks. 

leonz

Thank you for your post about gravity hot water heating and your home.
Is the coal room in your basement still open?

I use a coal stoker boiler to heat my very old home with fin tube baseboard.
I wish I had cast iron radiators instead for the greater thermal mass they provide.

Mad Dog_2

I LOVE that Green Boiler...Lime Rickey! If I ever get out to Michigan, I'd love to see your system.  It's BEEN MAGNIFICENTLY maintained. That's Smithsonian Qaulity...Mad Dog 

TheUpNorthState88

leonz said:

Thank you for your post about gravity hot water heating and your home. Is the coal room in your basement still open? I use a coal stoker boiler to heat my very old home with fin tube baseboard. I wish I had cast iron radiators instead for the greater thermal mass they provide.

Yes! It is. Plumbing and electrical runs in there as part of the kitchen is above. Even that insulation there under the floor is vintage Philip Carey Manufacturing rockwool. Had to remove a piece and under my floor is perfectly preserved. Not a trace of moisture or rot to be found. 

TheUpNorthState88

Mad Dog_2 said:

I LOVE that Green Boiler...Lime Rickey! If I ever get out to Michigan, I'd love to see your system.  It's BEEN MAGNIFICENTLY maintained. That's Smithsonian Qaulity...Mad Dog 

I would be honored to give you a tour of my home’s heating system. Not everyone would even care about this type of stuff, so it’s nice when you do meet others who do. 😃

leonz

You have an original Marsh Instruments triple gauge and an original David Honeywell clamp on aquastat.

The neighbor of a fellow HH member has a top fed gravity hot water system in a one floor home in New Mexico with a gauge just like yours.

reggi

DanHolohan said:

Beautiful. Please pay attention to the mercury in the Honeywell Heat Generator. Thanks. 

The way that's mounted I doubt it would be easy to "Kick over" 😉

Mad Dog_2

Same goes here. As long as The Wife (Barbara) says the house is up to snuff, I'll show anyone who is interested my system. Mad Dog 

TheUpNorthState88

leonz said:

You have an original Marsh Instruments triple gauge and an original David Honeywell clamp on aquastat the neighbor of a fellow HH member has a top fed gravity hot water system in a one floor home in New Mexico.

Wow! I had googled the Marsh company and saw they are indeed still in business and making gauges today but I couldn’t find nothing on the Aquastat beyond modern day ones. So I had no idea on its age if it was “original” or something added later in the 60s,70s, etc. 

leonz

Yes, it is original, and I am sure it was there when they were burning Anthracite coal to heat the home.

I have a 4 inch square bottom 3/4" tapping Marsh Tridcator on my coal stoker boiler that replaced the chinese junk and 2 defective hydrostats that came with the coal stoker that failed.

I added a Bell & Gossett RB-122-E low water cut off and a Honeywell L8124L triple aquastat when the hydrolevel 3250 plus units failed and I have slept well since 2017.

PRR

leonz said:

You have an original Marsh Instruments triple gauge...

Marsh does not call it a "triple gauge", they say "Tridicator".
https://marshgauges.com/
https://marshgauges.com/wp-content/uploads/2023/10/marsh_instruments_catalog_c5d248d6c5.pdf 43MB PDF catalog
That type, simplified to be moderner, is on paper page 107 (54 in PDF pagination). There's a simpler type on the page before.

I didn't look for prices. Willie: as a Proud Owner, if you need service, I would call and chat to the oldest guy/gal in the warehouse. They may have usable parts on shelves not in the catalog.

mattmia2

What is the control on the post below the disconnect?

I think the gas burner and therefore the aqua stat are a retrofit albeit early. It looks like there are dampers in the flue to regulate the draft with coal. Is it natural gas or propane? The distribution network for those didnt really get built until after wwii. There has been town gas since the 19th century but the gas works really only produced enough for lighting and cooking in most cases.

mattmia2

Oh, I see, it is a basso switch from the old gas valve.

Is that crawlspace pyrobar?

Intplm.

Beautiful. I bet it feels as nice as it looks.

TheUpNorthState88

mattmia2 said:

Oh, I see, it is a basso switch from the old gas valve. Is that crawlspace pyrobar?

I had to Google pyrobar but reading what that is, no it is not. 

EdTheHeaterMan

So many of the fossel fuel burners were installed in the lower ash pit door. that was not the best design for transferring the heat from the flame to the crown sheet of the boiler. Before WW II that boiler was designed with coal fire in mind. the gas burner you have is installed in the fire door, not the ash pit door. That may account for some of the efficiency you are experiencing compared to the oil burner and gas burner conversions and the Original Equipment oil and gas burners that were installed in the 40's and 50's

I have modernized* many coal boilers that were similar, we removed an old oil burner from the ash pit, covered over that bottom door, filled the old combustion chamber with vermiculite and set a fire brick floor about 6" below that fire door. The we would fabricate a new steel fire door with the oil burner mounted on that door and the fire tube set in fire brick cement. That project along with the modern flame retention oil burner was guaranteed to reduce the fuel bill. Putting the fire back up at the fire door, actually ended up sealing the massive air leaks in the boiler base and fire door. Put all that savings together and many customers were able to keep the heater that was still in good shape, and cut the fuel usage in half.



See how the manufacturer's suggested burner location actually makes the fuel oil and gas burners less efficient by design?

You've got a master piece there!

*We called installing a new oil burner in an old heater a Modernization. because it included more that an oil burner. It included a new combustion chamber, vent pipe connector, barometric draft control, high limit, primary control, other operating control(s) circulator relay or fan relay, relief valve, and T87F thermostat. So basically the old boiler or furnace was just like new!

TheUpNorthState88

EdTheHeaterMan said:

So many of the fossel fuel burners were installed in the lower ash pit door. that was not the best design for transferring the heat from the flame to the crown sheet of the boiler. Before WW II that boiler was designed with coal fire in mind. the gas burner you have is installed in the fire door, not the ash pit door. That may account for some of the efficiency you are experiencing compared to the oil burner and gas burner conversions and the Original Equipment oil and gas burners that were installed in the 40's and 50's I have modernizes many coal boilers that were similar, we removed an old oil burner from the ash pit, covered over that bottom door, filled the old combustion chamber with vermiculite and set a fire brick floor about 6" below that fire door. The we would fabricate a new steel fire door with the oil burner mounted on that door and the fire tube set in fire brick cement. That project along with the modern flame retention oil burner was guaranteed to reduce the fuel bill. Putting the fire back up at the fire door, actually ended up sealing the massive air leaks in the boiler base and fire door. Put all that savings together and many customers were able to keep the heater that was still in good shape, and cut the fuel usage in half. See how the manufacturer's suggested burner location actually makes the fuel oil and gas burners less efficient by design? You've got a master piece there!

Thank you Ed!! This is freaking awesome to hear from a seasoned professional. Someone in history knew what they were doing here when they converted it. When I was just causally googling Ideal Boiler No 7 just to see what was out there, I do see pics of others with theirs mounted at the bottom. So to hear you say mine is in the Ideal 😉 location just warmed my heart! 

EdTheHeaterMan

TheUpNorthState88 said:

Thank you Ed!! This is freaking awesome to hear from a seasoned professional. Someone in history knew what they were doing here when they converted it. When I was just causally googling Ideal Boiler No 7 just to see what was out there, I do see pics of others with there’s mounted at the bottom. So to hear you say mine is in the Ideal 😉 location just warmed my heart! 

I don't think your thermostat can help you with that.

GGross

They even painted the old honeywell heat generator gold!

TheUpNorthState88

GGross said:

They even painted the old honeywell heat generator gold!

Yup, all me. This started out that I was only going to repaint my boiler and it turned into painting everything on the system 😜😂

retiredguy

In addition to the description that @EdTheHeaterMan wrote as to the efficient way to convert a coal unit to a fossil fuel unit by firing through the fire door, the same is true for commercial boilers.

EdTheHeaterMan

retiredguy said:

In addition to the description that @EdTheHeaterMan wrote as to the efficient way to convert a coal unit to a fossil fuel unit by firing through the fire door, the same is true for commercial boilers.

Coal is a "Fossil Fuel". We would differentiate between Coal and Oil by saying Hand Fired or Automatic Fired. "With the touch of a dial" ...however, coal can also be automatic fired with a motorized stoker. But those still needed more maintenance to clean out the coal ashes regularly.

HVACNUT

I don't believe I've ever seen a conversion using atmospheric burners. I assume the electric disconnect means 120 volt controls, but with a gravity system, wouldn't millivolt be the way to go? (IDK if millivolt was around in the '30's.) I mean if you're gonna stick it to the man, twist it a little. Make him feel it. Was there a "conversion burner company" that made these setups on order? IOW that same setup wouldn't fit an American Standard Arcoliner. And even American Radiator offered a retrofit power burner, although obviously in the wrong location, right, Ed? If we all had 80's knowledge in the '30's, who knows where we'd be now? I'd probably be writing this from Mars after Arnold unharnessed the oxygen. Pretty cool, whoever made it.
I see individual gas cocks for each burner on the manifold. They're not full open. Are there not orifices, and that's how pressure is regulated? Couldn't the cocks be full open and adjust the gas valve manifold pressure accordingly?
Are the bottoms of the burner tubes open? It's an attempt at sealed combustion, but how does combustion air get to the burners, any crack available?

It's a very beautiful system... but, I would modernize it some by adding a Spill switch at the flue damper, and a Rollout switch or two somewhere near the burners. A low level CO detector for sure. If there's one thing we learned from the old equipment, it's safety matters. 

SgtMaj

What a great system!

TheUpNorthState88

HVACNUT said:

I don't believe I've ever seen a conversion using atmospheric burners. I assume the electric disconnect means 120 volt controls, but with a gravity system, wouldn't millivolt be the way to go? (IDK if millivolt was around in the '30's.) I mean if you're gonna stick it to the man, twist it a little. Make him feel it. Was there a "conversion burner company" that made these setups on order? IOW that same setup wouldn't fit an American Standard Arcoliner. And even American Radiator offered a retrofit power burner, although obviously in the wrong location, right, Ed? If we all had 80's knowledge in the '30's, who knows where we'd be now? I'd probably be writing this from Mars after Arnold unharnessed the oxygen. Pretty cool, whoever made it.
I see individual gas cocks for each burner on the manifold. They're not full open. Are there not orifices, and that's how pressure is regulated? Couldn't the cocks be full open and adjust the gas valve manifold pressure accordingly?
Are the bottoms of the burner tubes open? It's an attempt at sealed combustion, but how does combustion air get to the burners, any crack available?

It's a very beautiful system... but, I would modernize it some by adding a Spill switch at the flue damper, and a Rollout switch or two somewhere near the burners. A low level CO detector for sure. If there's one thing we learned from the old equipment, it's safety matters. 

I am not modifying the system in no way shape or form at this point. I do agree, safety first. I have CO detectors on every floor of my home and actually two in the basement. One CO/Fire detector combo and the previous owner left a plug-in combo Explosive gas/CO detector. So trust if any gas leaks, I will know right away!

Tom Sherman

Wow! What a great post! Thanks for inviting us into your heating system! 

Adk1guy

Nice to see a rare homeowner who recognizes and values something old but good. I've been selling my 4 unit with one of the few original gravity systems left in town and it has the original boiler. I'm sure every potential buyer is getting expert advice from some young parts swapper and is deducting the cost of a new boiler and so I have to accept the cost of a replacement boiler, conversion to forced hot water, and asbestos abatement is coming off the top.

TheUpNorthState88

Adk1guy said:

Nice to see a rare homeowner who recognizes and values something old but good. I've been selling my 4 unit with one of the few original gravity systems left in town and it has the original boiler. I'm sure every potential buyer is getting expert advice from some young parts swapper and is deducting the cost of a new boiler and so I have to accept the cost of a replacement boiler, conversion to forced hot water, and asbestos abatement is coming off the top.

Yes, I actually got excited seeing the old boiler when I did the showing and the radiators. While I’m only 35, I grew up in Detroit and two of my childhood homes had radiant heat through radiators. Now that I’m older and actually got an interest in these. I can confirm my first childhood home was steam (I got the burn scar on my ankle to prove it 😅), the second was hot water system. 

It’s sad because HVAC companies push forced air and people are falling for it. I get some homes that are rehabs and been exposed to the elements for decades systems can’t be saved, but you have people with perfectly fine working systems ripping them out to install a furnace. My house would need two furnaces to properly heat it. 

MarkMurf

  So as a youth back in Bayonne N.J., with the advent of the 3450rpm, retention head, oil burner, we retro-fit 100's into such boilers. This to increase efficiency during 'the energy crisis' of the 70's. The American Radiator Co. and Standard Sanitary Co. had both been in Bayonne pre-WW2. They merged to create American Standard. Being a peninsula on N.Y. harbor and Port Newark, Port Jersey, and Port Elizabeth, I've been told a large chunk of business came thier way in the manufacture of 55 gallon drums for the war effort. My father, grand father and extended family were in the coal and ice, heating and heating oil business as well as bulk haulage for just shy of a century. My father was the heating man at the company. A WW2 submariner vet, nothing was done half-****."Do a job, great or small, we do it well, or not at all." "Leave it looking better than you found it." "Leave it looking like someone was there." Before we moved forward with the new 3450 oil burner, we first identified the boiler as a 'wet base', 'wet leg', or 'legless'. The legless type were rare but out there. It effected how we set up the new combustion area. Not requiring the classic combustion chamber, if the boiler was wet base we would simply cut a hole in the 'observation' door and mount the flange and burner on that door, throw some KOA-WOOL on the target wall, to lessen abuse on that spot on the cast iron. These installations worked so well, that my uncle, who was in charge of fuel oil delivery would comment that the fuel oil usage was noticibly less on such buildings.
"Better than losing the customer to natural gas." My father's patented response. Now living in Montana there are still many gravity flow 100+ year old systems and similar warm air, (no fan) systems still chugging away. Built in the hay day of American manufacturing, done correctly, many, many are trouble free, comfortable and heat these homes at reasonable cost and dependability. "Just cuz it old, doesn't make anything wrong with it." Right Dad. 

ToddfromAkron

WOW, what a wonderfully maintained system!! Kudos to you and all those before you who've resisted the urge to "upgrade" to a worse system. I love the radiator colors. Keep up the good work. Todd from Ohio

Tom Hopkins

Great Post! We've lived in our 1929 House for 30 Plus years. We've been tempted to "update" our gravity hot water system over the years, but it just doesn't make sense. Our system is easy/low maintenance, dead quiet and reasonably efficient. Every month we marvel that our gas/electric bill runs almost half of our cell and cable/internet bill. Our averaged utility billing is about $170 a month and we live in North Dakota. Whenever we get a plumber, HVAC guy in for something they marvel over our system. It's almost as if we have a classic car in the basement.

jep

Thank you so much for sharing! I love all of the "turn of the century" radiators and the display of colors show how versatile they are for any decorating mode!. My radiators look very similar (house built about 1907) but have no identifying model - - - just floral decorations. Our American Standard Boiler was installed in 1957, looking quite similar, but much simplified. (Less is more). The expansion tank in the attic was still there but disconnected by the time we moved in in 1961. We just have to "bleed the radiators" regularly (esp. the one on the third floor) to keep them filled and stop the gurgling in the pipes. The last service people didn't even suggest adding "thermal expansion tanks" as they did at my brother's. Thank you for sharing . . . . and maybe I should "gold plate" the pipes in the basement as well!

jep

TheUpNorthState88 Thanks for sharing the URL for the pdf for the Standard Radiator Models. Most of the radiators in my house have floral designs, but I always wondered why two "low radiators" were "plain". They are just "standard four column plain". Maybe the floral ones were out of stock? The budget got tight? The answer is lost in history!

TheUpNorthState88

jep said:

TheUpNorthState88 Thanks for sharing the URL for the pdf for the Standard Radiator Models. Most of the radiators in my house have floral designs, but I always wondered why two "low radiators" were "plain". They are just "standard four column plain". Maybe the floral ones were out of stock? The budget got tight? The answer is lost in history!

LOL, I always wonder what the original story was on why 4 of my radiators are different brands. Especially since so many of them are American Radiator Co branded ones. Like were these others ones on clearance or on sale for the month?

TheUpNorthState88

Tom Hopkins said:

Great Post! We've lived in our 1929 House for 30 Plus years. We've been tempted to "update" our gravity hot water system over the years, but it just doesn't make sense. Our system is easy/low maintenance, dead quiet and reasonably efficient. Every month we marvel that our gas/electric bill runs almost half of our cell and cable/internet bill. Our averaged utility billing is about $170 a month and we live in North Dakota. Whenever we get a plumber, HVAC guy in for something they marvel over our system. It's almost as if we have a classic car in the basement.

An original Arco Red Flash Boiler! Very nice and I feel the same as you. Why mess with a perfectly fine working system? My boiler has been working for 87 years. There is nothing out there upgrading to. Some boilers fail within 8 years these days. And yes, no crazy bills. Even during that polar vortex at the beginning of year, my gas bill portion was $230. This below is this month's bill. The boiler, stove, fireplace, and water heater are all using NG.

johnlobb

What a fabulous system! We once had a home in Trenton, MI that had a gravity hot water boiler with millivolt controls. We had heat during any power outage! The comfort of that system was great. What town in Michigan do you live? I would love to see your system.

Tom Hopkins

We used to put a folded blanket on our front-room radiator. Talk about kitty-magnet!