Jeff Flowers on December 17, 2013 43 Comments In the spirit of the season, over the last few weeks we have been breaking down the pros and cons of different types of heaters that you may come across. The next heater on our list is the radiator heater, an old-fashioned way to keep your family warm. Invented in the mid-1800s, the concept of radiator heaters has a long history of keeping people warm. Over the years, this type of heater has slowly evolved into the low-maintenance, energy-efficient heaters that we know today. While it’s definitely not the most popular type of heater nowadays, it still works great at keeping you and your family warm. Let’s take a look at how a radiator heater works, the pros and cons of owning one, and whether it’s the right fit for you. Photo Credit: NZGabriel / Flickr How Radiator Heaters Work There are two main types of radiator heaters that you should know about — Electric & Steam. Steam Radiators Steam radiators work by boiling water to create steam. That steam then travels up a set of pipes into the radiator, which in turn, heats up the room via radiation and convection. As the steam travels through the unit, it slowly cools down and turns into condensation. This condensation then goes through the unit, ending it’s travels back in the boiler, where it is ultimately turned back into steam. This is the old-fashioned radiator heating method. It would be unlikely for you to find this type of system in newly built homes. However, this type of radiator heater is still in use around the world today, but it is no longer the preferred method of warming up your home. There are a couple versions of steam radiators that you could choose from, if you’ve decided that this is your preferred heating method. These options would include: Cast-Iron free standing systems: The oldest version of a radiator heater, the cast-iron system is very efficient at heating up the room. However, it also takes up the most amount of room, and takes the longest to heat up. Despite these two obvious downsides, the way it’s designed allows the cast-iron system to also hold that heat for the longest period of time. Baseboard Steam Systems Not to be confused with your typical electric baseboard heaters, this type of steam radiator works on the same premise of steam rising and condensation falling, however, they take up very little room in your home. You can run them along the baseboards of your home in a very discreet manner. Ceramic Systems This is the newest version of a steam radiator. Unlike its predecessors, it’s not hot when you touch it and it’s more efficient at supplying sustainable heat. If you were going to choose a steam radiator to heat your home, this would be the one you should look for. Electric Radiators This type of radiator is typically built in similar fashion as a steam radiator; however they utilize a different method of creating heat. At a radiator heater’s core is a metal reservoir filled with a special mineral oil. This mineral oil, more aptly referred to as “thermal oil” or “heat transfer oil,” is not burned in the process of heating, so it does not need refilling or replacement. It has an uncannily high boiling point and specific heat capacity, which allows small volumes of the oil to emit remarkably high quantities of thermal energy without evaporating. Evaporation causes unsafe levels of pressure to build up in enclosed spaces, so its absence from this process makes radiator heaters much safer. At the bottom of the heater is a heating element similar to what is found within an electric stove. It is electrically powered and is used to heat up the oil. Once the oil is heated, the warmth is convected throughout the body of the heater, warming its walls. The heat is then conducted through the metal walls and radiated into the surrounding space, filling the room with wonderfully cozy warmth. 3 Benefits of Radiator Heaters There are many benefits to having a radiator heater. It must be noted, however, that you can also find many of these same benefits in other types of heaters. 1. They Are Safe: First and foremost, the main benefit is the level of safety offered to the end user. Many portable radiator heaters come equipped with a tilt sensor, which cuts the power if a radiator heater is unbalanced or knocked on its side. The heaters also retain heat well, which makes them ideal for extended use. While it’s still not advisable to leave flammable materials draped over their surfaces to dry, they are much less of a fire hazard than other forms of heaters, such as space heaters that require more safety considerations. Lastly, they do not emit any harmful odors, gases or chemicals when used, unlike many gas heaters that require ventilation to be installed. Please Note: Some radiators will become hot when they start to produce heat. More on that below. 2. Less Maintenance: Radiator heaters also require much less maintenance than many of their competitors do. They do not contain any fuels that need replacing, and ventilation (or lack thereof) does not compromise warmth. Make sure you buy one that has a built-in adjustable thermostat, as this will help prevent wasted heat and lower you’re overall energy usage. 3. Reliable: For the most part, radiator heaters are extremely reliable. If you installed a cast-iron radiator in your home today, it’s likely that it will last for years and years – and in some situations maybe even decades. This isn’t always the case, which is why you should thoroughly research every product and brand before you purchase one. 3 Downsides of Radiator Heaters Just like everything in life, the benefits of radiator heaters also come with their own set of downsides. To some, these may not be a big deal, but they’re worth noting so that you can avoid a surprise down the road. 1. May Become Loud & Noisy Some radiator heaters, especially steam radiators, can become noisy over the course of time. If you live in an older home with an old radiator heater in the corner, then you’ve probably heard random noises coming from your unit. These may include squeaking, banging and whistling. These unwelcome noises become very annoying for many homeowners. If you’re experiencing this, it would be wise to call a plumber to come check it out. 2. Needs Air Flow Another downside of a radiator heater is that it must have proper air flow around the unit to effectively disperse heat around the home. Without this air flow, it’s impossible to thoroughly heat your home. Of course, different size radiators will create different amounts of heat. But, creating the heat isn’t the problem here. It’s getting that heat across the room that can be somewhat challenging. Especially if you have limited space and there’s stuff crowding around the unit. This isn’t a problem with other popular types of heaters available to you. 3. Hot to the touch The biggest downside, in my opinion at least, is that some radiators will become very hot as it starts to produce heat. If you have something touching the unit, such as drapes or a couch, then it may get damaged or catch fire. If your children or pets touch the unit, they may get burned. While this isn’t the case with all radiator heaters, it is definitely something you should consider when researching which heater is best for you. Tips for Utilizing Your Radiator If you have a radiator heater mounted on an exterior wall of your home, then it’s possible that you may be losing some of the heat produced to the outside elements. This is particularly true if that exterior wall has poor insulation, has drafty windows/doors nearby or the radiator is recessed within the wall. One trick that you can do to prevent this heat loss, is to add your own heat-resistant insulation directly behind the radiator. A sheet of foam insulation with aluminum on one side will work great at accomplishing this. You can make your own with tin foil and insulation, or buy a pre-made sheet at your local hardware store. Simply slide this sheet of insulation between the wall and the heating unit, with the aluminum face the heater. This simple trick will help prevent the heat from slowly seeping out of your home and redirecting it back to your living area. While it may not complement the rest of your décor, this small addition will cost less than $20, but instantly start saving you money on your energy bills. Are Radiators Better Than Other Heaters? The answer to this all question all depends on your situation. For most people, a different type of heater would probably suit them better. This is due to the heat being able to travel further. As the years go by, heating methods become better because the technology inside them evolves. One hundred years ago, there was nothing better than a radiator heater. Nowadays, however, you may be better off with a different kind of heater that produces similar amount of heat and disperses it around the room more efficiently. But, you need to take a look at your living situation. If you live in the Northeast where it snows most of the year, then a permanently installed radiator heater or wall-mounted heater may be the best fit for you. If you live in the south where it’s only cold for a few days out of the year, then you would be better off with a portable space heater that disperses the right amount of heat, but is easy to store when you don’t need it. Is it the best heater for you? All in all, radiator heaters are an incredibly versatile and affordable source of supplemental heat. They are reliable, durable, low-maintenance and energy-efficient. While it may not be the best, it’s still a great unit to help you follow a supplemental heating strategy. Whether you use a radiator, wall heater or baseboard heater, having a smaller source of heat that doesn’t require you to warm up the entire home will save you money in the long run. Just make sure that you read about the pros and cons of a radiator, as it may not be the type of heater for you. More Tips For Staying Warm: Wall Heaters 101: Your Complete Guide 6 Tips to Save Money on Winter Heating Bills 4 Benefits of Baseboard Heaters How to Prep Your Furnace for Winter Infrared Heaters: Your Guide to Staying Warm & Saving Money
Billie says January 9, 2014 at 3:53 pm I have the standing radiator heaters all over my house. As you said you can put the temp for that room and not the same all over. Also the oil in them last a long time, because you can keep the heater low and at an even heat. But I have a question. When the oil leaves the heater is it safe to keep using it? Because it still heats and gives out warm air. I have about 3 in my house that has given out of oil but I still use them. So I need to know is this safe to do? Thank you. Reply
Dale says November 10, 2014 at 6:30 pm My wife and I live in an 80 year old house with Hot water cast iron radiators, and I just learned about this method of insulating between the wall and the radiator which sounds like an easy quick fix to save some heat. My question is how do you recommend attaching barrier insulation to a plaster wall, and does the thickness of the insulation make a difference? I don’t know if I want some type of permanent adhesive stuck back there in case I choose to remove the insulation later.The radiators already have nicely designed wooden covers so I guess the insulation wont be visible. Another question is that these wooden radiator covers have screens on the front side to allow heat to flow out, but the top of the wooden covers which are a foot deep are closed and we simply use them as shelves. Should the tops of these covers be opened with screen also since my thought is that heat rises and is otherwise trapped under the cover? Thank you for your response. Reply
Tasha says November 15, 2016 at 11:48 am Hi! I am in the same situation. If you happen to get feedback, please share (with me). Thank you! Reply
debbie says January 29, 2015 at 10:57 pm my dad is re-tired Pipefitter They have registers all over and he put down pipe’s under the floor including the basement floor you never had to go over 71 in below zero.house was alway’s warm.and are skin was never dry that is the way to go radiant heat no forced air,It caused allergies dust that can’t excape I miss it Reply
John says November 12, 2015 at 3:29 pm I don’t see any answers to these questions.Are there no answers? Reply
Regina Hatchet says November 14, 2015 at 5:23 pm My son-in-law just installed a Fireplace Insert into the actual fireplace. It has blowers on both sides, you still put firewood in it. But smaller 18″ pieces only. Question. He has not used it, just installing today. He wants to insulate the insert all around the entire outside which will never be seen, but will help keep wind from blowing down the chimney thru any cracks anywhere. What do we buy to insulate it with? A special kind? Please advise. Reply
codie says December 2, 2015 at 3:00 pm Why is it Regina that the thread about types of radiators the place you choose to post your question about how to insulate a chimney for a wood burning fireplace? Reply
Emma Noe says December 23, 2015 at 2:28 am Being from Europe, I am not too happy with blowing air. My feet are cold all day, and I would like to try the old fashioned system, quiet, and nor cooling air. Reply
Richard says January 31, 2016 at 12:30 pm I am taking apart a bad steam radiator and have another to get parts off of. What do I use to hold the sleeve in place, there is no O ring. Reply
Phil Light says February 9, 2016 at 8:34 am We have a cast-iron boiler radiator system throughout our home. Recently, we left for vacation, set the system on 50 degrees and came back to some burst radiators from freezing. We don’t want to change systems but must replace several of the radiators. Where can we find them? Reply
Angie Emsick says December 6, 2017 at 12:28 am just reading your post and wondered if you found replacement radiators? Reply
Amy Hiles-Maynard says January 26, 2018 at 5:31 am I’m in exact situation you describe. Did you find replacement radiators that fit a 1900 decor? Reply
maian conn says March 31, 2018 at 10:51 am you can put anitfreeze in radiators…. not sure where you get the antifreeze special for furnace radiators. . Reply
Nash Rich says March 8, 2016 at 4:38 pm I’ve only had a little electric heater that was portable. I don’t think it had one of those sensors that turns off the unit if it tips over. I didn’t know that kind of thing existed. I think that’s a really good idea. I think safety is really important. My parents had the small radiators against the walls and my dad always made sure we didn’t have anything against them. So I think that kind of thing is good to consider. Reply
Maureen says November 1, 2016 at 3:02 pm I live in a 1937 colonial my upstairs is usually quite cool. When I turned my heat on last week, I was so happy to have flowing and feeling really hot! That only lasted for a short time and the next morning they’re cool to the touch. What is the knob on the radiator near the floor for? I have never touched it. Could it be a turn off valve and the reason it’s pretty cold upstairs? Reply
mIKE hUNTER says January 9, 2017 at 10:49 am 30 YEAR OLD GAS CENTRAL HEATING WATER TANKS ETC, RADIATORS HOT BUT WATER NOt GETTING HOT, BOILER FIRED UP AND GOING ok ? Reply
Suzanne Deneau says February 13, 2017 at 7:45 am I have a home full of radiators but the boiler is no longer in the home. I would love to sell them if anyone out there would like to pick them up. Very cheap. Just would like more room in the house. A furnace has been installed. I’mlocated Iin flint Michigan if anyone is interested. Reply
sam smith says June 7, 2017 at 7:42 am This guide is amazing as to figure out the solution for a problem long been in the homes—one room is extra hot than other rooms. With this, one can install the right system according to the requirement and size of the room. Reply
Patricia Moss says August 17, 2017 at 12:14 am I have an antique heater and would like to know the price it’s worth. It doesn’t have a radiator. It’s the kind you can boil water on top of it. Reply
Angie says August 30, 2017 at 6:10 am Is it possible to install a cast iron radiator in a fireplace? Reply
Upnorth says November 15, 2017 at 1:29 pm Yes, I have seen cast-iron radiators installed in an old fireplace that has had the flue damper permanently sealed. Reply
Jim says April 4, 2018 at 1:55 pm You can also buy a special radiator that goes in the fire place and is hooked into the radiator hot water system. You then start a fire over/against this “radiator” and it heats the water for the entire system. plus you get the bonus fun of a fireplace. Reply
Lucy Huggins says September 17, 2017 at 5:57 pm Hi! I have a 3 bedroom, 1 bath home, my question is How can I take the electric radiators, buy several of them and connect them to each room I’m my house, what piping would I use to connect them? Reply
Dsw says September 24, 2017 at 12:11 pm I’m new to radiator systems, but I understand that at least once a year you have to drain out a little water using a valve at the lowest point in the system because the water can collect rust over time. Then there’s another valve somewhere in the system that’s connected to your house water supply. Use this to refill your radiator system before you use it. NEVER FILL IT WHILE THE BOILER IS HOT! If your boiler is running but the radiators are cool, you probably need to top off the water. Again, WAIT UNTIL THE BOILER COOLS DOWN FIRST. There should be a water libel gauge somewhere near the boiler to indicate that you have it filled correctly. Reply
maian conn says March 31, 2018 at 10:55 am my boiler came from junkyard fifty years ago … have been using always , have radiator antifreeze in radiators and never drain …. never in 50 yr drained anything … Reply
Ken says November 16, 2017 at 5:18 pm I am new to this style heat. I recently moved into a home attached to a commercial building. My heat is all baseboard heaters thru out the perimeter of the home. It then connects to an attached garage. As far as I can tell there are no separate devices to control room by room. I would like to lower the temp in the master bedroom for sleeping. Is there someway of doing this? Could I cover the covers with blankets or towels or would that cause a fire hazard? Any advice would help. Reply
Shelly R says November 21, 2017 at 10:39 am Yes, that valve is what regulates flow of water and gets water upstairs from boiler. Turn it right to shut it completely off and left to open it all the way. Keep turning left till you cannot turn it left anymore. And vice versa This is open all the way. Anything in between is partial. Like your sink per say. Hope this helps. One leading directly up from kitchen to upstairs bedroom will cool or heat bedroom, etc. My apt is same way. Neighbor below freezes me often by closing HER valves! (OH) My bedroom remains 64 or 66 Deg when 32 Deg outside.Hope this helps you! 🙂 Reply
Mike says December 7, 2017 at 7:28 pm Question: is it safe to run an old gas boiler when the ball and grosset circulator pump is not working. The boiler is in the basement, the radiator on the third floor is boiling hot, second floor radiators are warmish, first floor radiators are barely warm Thanks!!! Reply
Scott says December 22, 2017 at 7:33 pm Another huge benefit of radiators vs air vent heating is it doesn’t dry your skin out. It just warms the air and there’s less warm air flow, which is far more drying. Reply
J johnson says February 2, 2018 at 2:54 am The same thing happened to me. Where did you find replacements? Reply
Joe Serrato says April 5, 2018 at 10:34 pm why am I not getting heat to the second floor. the first floor is very hot. but the second floor is not getting any water into the radiators. what can be wrong! call me baffled Reply
Nicholas says November 1, 2018 at 11:59 am The reason that radiators can get very hot on lower floors, but not that warm on upper floors is because of the build up of air inside the upper floor radiators that needs to be bled out. It’s actually hydrogen created by a very slow chemical reaction between the water and the radiator metal. This trapped air takes up space and prevents the hot water from circulating properly (only lower parts of radiator will be hot) and transferring its heat to the radiator metal which then would heat the room. To bleed out the air, first let the furnace run for around an hour until everything is as hot as possible. Then starting with the highest floors, look for a knob near the highest point of the radiator and carefully turn it to open. On some older radiators the knob many have broken off so you will need to use pliers or a wrench to get it open. After opening it you should either hear a hissing sound or water will come out. If water comes out, then there is no air to bleed so just close the valve. If you hear a hissing sound, look to see if the air is being expelled (usually), or getting sucked in (usually when radiators are still too cold). If air is getting sucked in, close valve and wait for radiator to get warmer because keeping it open will just make problem worse. If air is coming out, keep valve open, but put a rag or paper towel in front of it because when all the air is bled out, gross black water will follow and you don’t want it to spray out on anything. Sometimes air will start coming out, then slow down and stop, and then reverse and start going back in. If this happens, then just close valve when air stops coming out. After air stops coming out, or you see water, close valve firmly and move on to the next radiator. I have to do this every 6 months in our home, otherwise the top floors won’t heat properly. Good luck! Reply
Henry says January 8, 2020 at 3:23 pm You probably need to increase the speed of the water pump or get a bigger water pump. Reply
Mike says June 15, 2018 at 12:42 pm Im am trying to relocate some of my radiator Heat to a different location my question is do I have to use Galvanize pipe or can I use pex water line Reply
Candy says October 19, 2018 at 6:04 am Great questions but with limited answers. Why so? What is the use of asking these important questions when there are no answers? Reply
D. Reed says October 21, 2018 at 9:16 am Why was it not mentioned that in the 1800s this water heater system was invented by two African-American men? Reply
Rory says December 6, 2018 at 12:39 pm How do I get an old Edison Fireplace Radiator restored in Columbus, OH? I can provide a pic, if needed. Reply
David Chapman says February 19, 2019 at 11:56 am To Joe Saratto – If you are not getting heat to your upstairs radiators, try one of two things. Verify you do not have a valve turned off going upstairs of there are 2 separate loops. Or, try bleeding the upstairs radiators of air. Reply
Robby Buckmire says January 19, 2020 at 3:21 pm How do I get the old radiator working , it not sending out any heat Reply
Frances Guevara says January 21, 2020 at 3:52 pm Looking for Old Version Cast-Iron Steam Radiator Heater. About 50′ or 60′ long. Reply
