Want to replace radiators. Prewar Boiler ...Need advice
PW is fine when everyone is bidding in kind. I like to think I know what I’m doing but hey I rarely do! At least my bonding company thinks I know what I’m doing, so do my clients. 10 years in and still going strong. Those things count for something.
steam_man
in About Brooklyn 11 years and 2 months ago
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20 replies
parksloperower | 11 years and 2 months ago
I was told by national grid I have a prewar boiler and would last forever. Bought a row house 3 years ago and so far no problems. I know its a hot water system but I was curious what the black water tank hanging over the boiler is used for.. see attached photos. Does this mean its a gravity system? I’m looking to replace the radiators to slimmer units. Can I use hot water hydronic radiators? Any old timers out there that can give me advice on this beast? The plate on the boiler says National – US gas boiler. No 7-22\. Steam 330 sq.ft, Water 92000 BTU/HR, Input 153000 BTU/HR, Output 122400 BTU/HR Thank you
parksloperower | 11 years and 2 months ago
Photo attached
steam_man | 11 years and 2 months ago
First off I am not even 40 years old so you’re just going to have to accept the fact that us whippersnappers have some brainz too. That being the case…. The black tank is called a compression tank. It maintains the pressure in your system. As water heats up it expands. The compression tank gives it somewhere to expand to. It is an older yet still effective way to maintain system pressure. These days we don’t use compression tanks, we use expansion tanks. Same principle in reverse. In the expansion tank on one side there is a rubber bladder that is pumped full of a set amount of air, on the other side the tank is open to accept water from your heating system. It will only allow the amount of expansion as a factor of total system volume versus the volume of air in the bladder. If there is too much water or heat added tot he system it will get pushed out the vents due to the fact that the air bladder wont allow it any more space. This is the (typically) red or gray tank you see hanging above your newer hot water boilers. As for the National Grid comment of “your boiler will last forever”..Well so will a McDonalds hamburger, but you wouldn’t want it after 70 years either. A new hydronic boiler will be roughly 95% efficient versus your older one that is well…less than efficient at this age. Granny don’t dance that Charleston like she used to. Any other questions?
parksloperower | 11 years and 2 months ago
Thanks for the great reply. Made me laugh. Appreciate your expertise. I will start looking into a new hydronic boiler, not just new radiators. Any recommendations? Its a 15×40 row house. 3 Floors.
steam_man | 11 years and 2 months ago
Viessman or Triangle Tube. Your radiators are most likely fine.
resident2 | 11 years and 2 months ago
Your old boiler is better than any new boiler. The cast iron holds the heat better and the simple parts are much easier to maintain. Just as a 150 year old Brick or Brownstone townhouse is far better than the new construction being built today that is designed to be knocked down and build new again 25-30 years from now. With proper maintenance both your old building and old boiler will out last the new buildings and boilers. Look after it and as for the radiators; much as you may think the modern ones take up less space etc., the old ones are all balanced, and take more abuse than the new ones as well as being classic etc. With heating systems and especially a circulating hot water system (the best) if it isn’t broke don’t fiddle with it. If you said you had a steam system, yes they take more maintenance and the hissing and knocking followed by dribbles if you do not watch it can be a pain, I could see changing it. A forced hot air system….definitely change it. But a circulating hot water system that is all working fine? just look after it, change the burner if you want the most efficient system…tune it up and leave it alone. I have two buildings with old boilers and two with new boilers; the new ones are no more efficient and one has had to be replaced at only 5 years old, the seals in it went and it would cost almost as much to repair as replace.
BobMarvin | 11 years and 2 months ago
I’m inclined to agree with resident2 about keeping your old boiler and radiator–not that I know anything about hot water heating systems, but I’m firmly in the “if it ain’t broke, don’t fix it” camp. However I disagree with him about automatically replacing a forced hot air furnace (although this is irrelevant to the OP, who doesn’t have one). I’ve been living with one since I bought my house in 1974\. The biggest disadvantage (compared with the hot water heat in the brownstone apartment I previously rented) was that there were considerable swings in temperature–it heated the house fast. but the house cooled down quite a bit before the furnace went on again. Replacing my old electro-mechanical thermostat with a modern digital electronic model pretty much solved that problem.The advantage of a forced hot air system is NO RADIATORS, just attractive-looking 1899 hot air registers, and extreme ease of maintenance. All I have to do at the start of the heating system is change the filter, oil the motor, and check that there’s grease in the grease cups (and fill them every few years–I’ve hardly made a dent in the one pound can of grease I bought almost 40 years ago. Oh, and I changed the belt once, when I first used the furnace–that almost 40 year old belt is still fine. The only time I’ve needed service is to replace the automatic flue damper (which I had retrofitted c. 1979) which broke and caused the spill switch (another late ’70s retrofit, which guards against CO poisoning) to shut down the system. If my c.1965 furnace brakes down I’m sure I’d replace it with another
Master Plvmber | 11 years and 2 months ago
I turned 45 in January. Am I ok? The fact that your boiler’s just not on fire or actively shooting water out of it at the moment, but producing 5x the normal amount of carbon monoxide and running at 40% efficiency shouldn’t make you feel like “last forever” is a good thing. To last forever is not a great goal when talking about carbon based fuel-burning equipment that resides within the envelope of your home. Resident2 has had bad installations if he hasn’t seen a significant efficiency gain or decrease in fuel usage when going from old to new boilers. Sorry. Just the way it is. Steam Man knows his stuff. #truth.
steam_man | 11 years and 2 months ago
Thanks John.
eman134 | 11 years and 2 months ago
Your boiler and hot water heater are a really terrible old installation, and as mp noted probably incredibly inefficient.. That said, you an still change out your radiators to something like http://www.runtalnorthamerica.com/ or http://www.buderus.us/files/201003040246150.Panel_radiator_design_manual_12.2009.pdf Just get a heating professional to size them appropriately BTW get someone in sooner than later to correct the venting from your hot water heater…gas vent should never drop down before entering the chimney
ellenlourie | 11 years and 2 months ago
I rarely if never see quality new boiler installations. Meanwhile some 50-80 year old installations are done with amazing craftsmanship and quality. This is the reason they are still operational after so many years. I had seen mike honeywell (honeywell corporation) original radiator valves still operational. And today’s single entry conversion valves, imported from Europe are replica of mike honeywell 100 year old valves. But who knows about it. Look at iron fireman steam mini tube systems, marvel of engineering dated back to 1950\.
citigyz | 11 years and 2 months ago
When I moved in to my house in 1980, Bklyn Union Gas guy said that my 1965 Weill-Mclain boiler will give out soon. I took a chance and kept it. I have the burners cleaned every year and it works beautifully. The most efficient “green” machine is the one that already exists INMO. I also drive a 15 year old car that works great. Think of the energy used to make a new boiler (or car). How long is the catch up period to make up for energy bills of a new boiler? Call me crazy but I think we are sold things we don’t really need. My big turn of the century radiators work great and keep hot hours after the thermostat cuts off the boiler. My energy bills are minimal.
citigyz | 11 years and 2 months ago
Sorry, IMHO. Steam man knows his stuff but do you think he has a monetary interest?
Master Plvmber | 11 years and 2 months ago
My point is, define “works great”. You probably have no idea how much fuel you’re wasting by using a boiler of that age. It’s very simple. Every boiler ever produced, especially the cast iron types we’re very likely talking about, by nature of their design, develop a layer of internal crud that insulates the boiler water from the flame the fuel produces. That means heat being created goes right out the chimney and not into the radiators. Age does this. Every. Time. The next best concern for an old boiler is how much carbon monoxide it produces. The United States has 5 times the amount of CO incidents that all of Europe does and it’s because in most countries all homes, even single family residences, get an annual boiler inspection that includes a CO test as well as an efficiency test. If the boiler fails, the inspector has the “powers of the police” to remove the boiler from the home. Boilers in Europe are typically replaced every 15 years and when I attend conferences they are blown away that people in the US are willing to keep a gas-fired device for 40 years or more. Step one to a carbon monoxide tragedy is having a bad CO source. Step two is a venting problem. With a 30-year old boiler, you’re halfway there. I could go on, but the reality is, we keep boilers for far too long in this country because we convince ourselves it’s ok and it’s far easier to do nothing and spend more each month on fuel than to go through the replacement process, which is rather simple by now anyway. Sure, steam man and I have a monetary interest in changing boilers but there is plenty of work in this city for us without having to dole out bad information on a local community message board.
bobjohn | 11 years and 2 months ago
I want to weight in on the subject of “heavy radiators are better because they hold heat longer”. This does not make any sense. From energy conservation and 2nd law of thermodynamic if boiler produced X units of heat, the radiator will release exactly the same X units. The heat is not created by radiator neither can disappear. The thermal capacity of water is much higher then of iron. So the thermal capacity of radiator is mostly defined by its volume not by the weigh of the iron. In other words the heavy radiators is almost the same as the new light ones with the same volume of water. Finally the radiator with high thermal capacity would create a disadvantage because it add inertia to the system: you turn on the heat, but it takes longer to heat up. you turn off the heat since you do not need it, but it is still radiated by the radiator with high thermal capacity. Literally wasting the heat. As other stated, you should replace the heating with the modern high efficiency boiler. I also learned that replacing one zone with multiple zones will yeild some savings as well. For example I had an ancient boiler (originally fired on wood and then on coal and then on oil) with single zone. I paid $900/months in january 2008 (when oil was really cheap). I replaced with 85% efficient gas boiler with outside reset and 5 zones. I think I pay $300/month max since then. In addition, I do not need to think about oil delivery and maintenance and the bailsmen does not smell like oil and I do not need a room for oil tanks.
Master Plvmber | 11 years and 2 months ago
Bobjohn, you’re mostly right. The reality is that all radiators, because of the reasons you stated, operate at 100% efficiency every time. What energy goes in is released until an equilibrium is reached between the temperature of the radiator and the temperature of the air that surrounds it. “Wasting the heat” has been worked out of this equation long ago, and only would occur if some type of anticipator or other smart control isn’t employed that will determine the rate at which the building heats and cools. Anticipators, PID controls, etc, all shut the boiler flame before the thermostat setpoint is reached to allow for that bleeding off of latent, or passive, heat still in the radiators. Thank you for posting the good results of your new boiler installation. (edited for clarity)
steam_man | 11 years and 2 months ago
For the record, I have not installed a residential boiler since 2006\. The reason why is because I DO have a monetary issue. The issue is that I find it impossible to make any money on a residential boiler job. Therefore I give my advice (free of charge I might add) as a way of giving back to the community and even the universe (OM). Here’s what we install now (always did by the way). Now that’s a boiler.
ellenlourie | 11 years and 2 months ago
So. Cleaverbrook. Big deal. This is what I did at power plant. Build new one from concrete foundation up from zero. Then demolished old one. It is just a part. Most did not fit into the picture. And yet I think these jobs where no money are. On residential jobs you have human factor. You do good job you have loyal customers. And price is really not a determining factor. Commercial jobs are all about lowest bidder.
steam_man | 11 years and 2 months ago
Nice tank Gennady. We build those too. It looks like you did a beautiful job. I’m glad to hear you enjoy residential work, homeowners deserve good, qualified contractors to work on their home. It is obvious that you and I have differing views on most homeowner’s motivation when choosing a contractor. Either way, I choose to focus on public sector work, we excel at it, we know our clients and how to meet their needs. It works for us.