Emergency Candle Heater: Building a Single Candle Clay Pot Radiator

With cold weather fast approaching, I wanted to share a cool little project that I did over the weekend that can provide some extra heat during a grid-down emergency situation. With the heat from a single candle, it is possible to heat a small area during an emergency ­– if you can capture that heat.

Step One: Build a Small Emergency Shelter inside your home.

If you live in an apartment, or a house that doesn’t have a fireplace or wood burning stove, winter power outages can quickly turn into life-threatening emergencies. When the temperatures start to plummet, you need to take action.

The first step you should take is to build an emergency shelter, or warm room, within your home. It’s a lot easier to heat a small walk-in closet or pantry than it is to heat an entire home. So the first thing you want to do is find a small room or closet, and then start insulating.

  • Line the walls with couch cushions, blankets, or anything else you can find that can trap heat inside the room. Think about when you were a child and built forts in your bedroom; we’re going for a similar concept here.
  • If you have an emergency reflective blanket, putting one up can help reflect heat back into the room.
  • Depending how many people are in the room, body heat alone can be enough to keep the room at a tolerable temperature.

Step Two: Build a Single Candle Terracotta Pot Emergency Heater

Once you have your shelter built, a single candle can be used to help heat the room. Building a small Terracotta Clay Pot Radiator allows you to capture the heat generated from a candle, heat that is normally wasted, and slowly build it up inside a makeshift radiator.

The Single Candle Clay Pot Heater

Building the Clay Pot Candle Heater

The heater is actually pretty simple to make. One long bolt, a dozen washers or so, about 7-8 nuts, and a couple small terracotta pots is all you need.

Terracotta Pots
  • Place the Long Bolt through the Terracotta pot, separating each pot with a couple washers and a nut.
  • The Center bolt, washers, and nuts will all conduct the heat from the candle. The metal core will get extremely hot, trapping the heat and radiating it out to each clay pot.
  • The heat will slowly build up inside the pots, and then will begin radiating heat around the clay pots.
Inside the Clay Pot Radiator

I’ve seen this project on some other sites, where people suggest it can be used to heat a home for pennies a day; IT CANNOT!

This is in no way meant to heat a house or even a large room, but in an emergency situation, it’s a good way to capture heat from a candle and then radiate it out into a small area.

Candle Pot Heater

Staying warm during a winter power outage

During a winter storm, power outages can quickly turn into a life-threatening emergency. When the temperatures start to plummet, you need to take action. The first thing you should do is build a warm room. It’s a lot easier to heat a small walk-in closet or pantry than it is to heat an entire home. So the first thing you want to do is find a small room or closet, and then start insulating.

Urban environments are filled with materials that can be used to keep your body warm, and protected from the outside elements. Cardboard, foam, plastic, and bedding materials are just a few of the items that you should be able to easily find. During an emergency, a small room or closet can easily be turned into an insulted fortress.

  • Couch cushions, blankets, towels, and mattresses can all be used to add extra insulation to your warm room. Line the walls with these insulating materials to trap heat inside the room.
  • Layer your clothing, and remember that in an emergency you can line your clothing with crumbled up newspapers, paper towels, or any other insulating materials that you can find.
  • Depending how many people are in the room, body heat alone can be enough to keep the room at a tolerable temperature.

What can you do to stay warm?

Well hopefully you prepared for this kind of problem in advanced, but let’s look at some more options that you might have.

  • Top Solar Generators, Power Packs, and Emergency Solar Solutions – Invest in emergency backup power!
  • Wood Stove – If you don’t have one, get one! Even a cheap, used wood stove will provide more than enough heat to keep you warm during an emergency.
  • Backpackers Stove – A Small backpackers stove can be used to heat water. The hot water can then be put in water bottles and shoved into a sleeping bag to keep you warm.
  • Put on your Winter Gear – Hats, gloves, and coats. It may be uncomfortable to wear when you’re trying to sleep, but you’re trying to stay warm, not comfortable.
  • Tent – In your small warm room, you can also set up a small tent to sleep in. It will capture your body heat, and help you to stay warm throughout the night.
  • Dress in Layers and make sure you stay dry. If you start to sweat remove a layer at a time.
  • Eat Something – Eating can actually help keep you warm; it can be especially important right before bed. If you eat right before going to bed, the energy your body uses to digest your food can keep you warm at night.

Prepare Before it Happens: Stocking up on some of these items can help you prepare for winter power outages.

Shirts of Liberty

OFFGRID Survival book



  1. Actually… I have been using a Terra cotta heater for two months. It’s at 32 degrees outside today. 72 degrees in my house. They are excellent space heaters. Oh and by the way my furnace isn’t on. With these space heaters I have no need currently for my gas furnace. Tea lights burn for 4.5 hours.

    • are you truly able to heat to use these as space heaters?? it sounds hard to believe, i would even be happy to use it as a supplemental heat to save some money on my natural gas bill.

      • No. It is NOT a form of alternative heat. It will not heat a room that is an
        8 X10 . It is more like a foot warmer, but the pots do put out respectable heat, just not much of it…..Prepping For Your Survival

        • Think of it in terms of the 3 methods of heat transfer: conduction, convection and radiation. When a candle burns, it gives off light but mostly heat. This heat is lost almost entirely to convection and escapes to the highest point in whatever space it is in. When you build this contraption, you are capturing that rising column of air and trapping the heat in the pots. Once the pots warm up, they will radiate a considerable amount of heat, directed up at an angle. So this will be great as a foot warmer or to huddle around. It won’t heat your house as they said. Hot air rises, that’s why people in cold climates have traditionally built with very low ceilings.

      • Actually its not, like the author said its not meant to heat large areas. My son used this method quite often at his flat when it got really cold as the heating wasn’t adequate. It does take the edge off it kinda surprising how warm they can get

    • You must have a LOT of these to keep a house warm. I built one and it will keep a 4’x4’x6′ area comfortable. So unless you live in a cardboardbox or have multiple heaters. I say bullshit!!

      • Stupid idiot. Learn to read. It was clearly stated that this would heat or at least take the edge off the cold in a small closet, pantry or other small room for emergency. No one expects to heat up an entire house but a moron like you. Go freeze.

        • Ed, you should be careful with the name calling, as Marita, clearly stated, or claims, that it is 32 degrees out, and she says it is 72 in her house with the furnace off, and that she is heating ” her house ” with only terracotta pot heaters. To which the person you are name calling was replying to!!! Now who is looking like the idiot?

        • I say the bigger the flower pot, the bigger the emergency candle. Who says they have to be smalll?
          I live in a 480 sf studio. Think I’m going to try to use a slightly bigger size to assist if my power goes out. I have no storage space or tents to create smaller rooms. But 2 or 3 larger sized natural space heaters if the power goes out, I should be all set! Thank guys!

    • These terra cotta pot candle heaters work great. 2 Christmases ago we were without power. I built one of these with 3 pots, and 3 little candles in it nicely heated my large bedroom. It was around freezing outside and we “cricked” the window a little, and it still stayed warm. We were careful, when opening and shutting the bedroom door to do it quickly to keep the heat from escaping. We used 3 bricks in a u shape instead of rocks, just the right height to keep the candles burning. I made another similar thing from a glass bread pan and an overturned cooking pot, on top of it, candles inside the bread pan. I put a plate on top of that, and it heated half a can of corn at a time to eat.

      • Did you by chance make a YouTube video of that? I’d love to see how you did it. In Eastern Canada, the power goes out just about every winter when we get an ice storm.

      • One time, a homeless woman told me that she could stay warm under a small tarp using one of those little votive candles.

    • Wow, can you please post a photo and tell the approximate size of it? Did you make it yourself or buy it somewhere? Thank you in advance!

    • Insert a good candle in a little bottle half full with margerine, the cndle last for days and with two under your pot heating will be very efficient.

  2. Great Idea!!! Intend to build one as soon as I can. Don’t have a fireplace and with the weather being what it has been and will be, I definitely need this just in case of power outage.

  3. I have a wood stove but, I think I will build one just to see how well it actually works. I can always use it for a backup if for some reason I run out of wood.

  4. This is nonsense. A candle only can produce roughly 250 BTU/hour. This insufficient to heat any space of any significance. Plus since its burning inside, it consumes oxygen and produces carbon monoxide as well as carbon dioxide. In a small space, this could be toxic.

    • People used to only have candles (or lamps) for light in their houses at night. I could be wrong, but I doubt that one or two candles could cause significant carbon dioxide/monoxide buildup in a typical room (even a small room). That’s got me curious how a candle’s CO2 output compares to a human’s. Anyway…

      As far as heating, I’ve given this a lot of thought. There are 2 important questions. 1) What is the most efficient way to disperse/retain the candle’s heat? 2) Is heat added faster than it is lost?

      I believe the answer to the first question in this context would be radiating the heat (like from the clay pots). It helps spread out the candle’s heat more evenly and avoids pooling it at the ceiling (like convection).

      As for the second question, that is greatly affected by the room’s insulation and size. You said that the heat is insufficient to heat any significant space, and I agree that as a room gets larger it becomes much more difficult to heat, but it comes down to insulation. If you could retain 100% of the candle’s energy, you could eventually heat any sized room until it was insufferably hot…also, assuming you had a forever-candle. So it’s a question of area and heat retention; not just size.

      Of course, if you are in a large room without good insulation this would likely not be an effective heater. But it would still be a good emergency heater for warming a few humans who huddle close to it. Much better than trying to warm yourselves up over a bare candle flame.

        • I used the refillable candles from fire fly fuel. the flame stays at the same height as when you light it. Where wax candles slow go down.

      • Pre electricity houses were very drafty. This project involves insulating a small room – no heat loss/no air flow. If you sleep the night in such a closet you’ll at least wake with a headache if not dead. Fortunately a candle will not last all night. Nevertheless this is an irresponsible recommendation; there are no cautions mentioned.

    • I just checked out the c02 that candles put off,
      There was a post about being prepared for winter (January 6, 2017) things to keep in your car, I added a post about this clay pot heater and right away c02 was brought up. So I went to youtube.com and typed in c02 and candles. Sure enough burning too many candles can be dangerous, so people please be very careful when burning anything to keep warm in winter, not only does fire danger go up in homes in the winter, but now with this clay pot heater there is c02 danger.
      When I first saw the clay pot heater my thoughts were make several and or bigger as I live in a all electric home and there are times when power goes out. (Oregon Coast ) we are dealing with ice and snow right now.

      • CO2, Carbon Dioxide is what we breathe out, CO or Carbon Monoxide is the by product of fuels burning as is CO2. Large concentrations of CO will kill you as will CO2, but CO takes up sites on your hemoglobin in your body which is meant for oxygen, blocking it’s ability to carry oxygen and you suffocate and will die.

    • Robb your correct it can be deadly. My father and his hunting partner did this old boy scout trick im my dad little camper..they were found 3 days later in a coma. Both lived..one died a year later and my dad is currently in a nursing home because this ate holes in his brain and the shunt they put in his brain keeps failing.your the first person that I’ve ran across that knows the danger if doing this. Thank you for sharing

    • It changes the type of heat to radiant heat which makes a person feel warmer near the heat. Also, a tea candle or even a whole pack in succession is not going to fill a room with CO/CO2 no matter what.

    • OMG!! The candle heats the metal bolt, washers, and nuts and the pots allow the heat to increase before it radiates out. C’mon people use your brains. Just think if you put 3 or 4 of these units in a small room. Beats freezing to death.

  5. Hmmm I have to try this, but what if you used a different heat source, like a can of sterno for cooking, that’s meant to put out higher btus?

    • I tried using a 3 wick citronella candle….huge mistake I sat the candle in a pot (really glad I did). At one point the top of the candle really want crazy…slid the pot out and put it out in the bath tub….been using one in my bedroom for 2 winters now… I it stays comfortable…I did put up 3 layer curtain on my windows in bedroom… did think of the space blanket…might get a couple to add to the curtains…IL continue to use it. Candle only….

      • You do not use citronella candles inside, ever! For some reason, they are toxic. Directions on the label always say to use outside

  6. this does not work, i went out and bought all supplies as i have small room in my home and i wanted to test the theory…FORGET IT…SAVE THE $26.00

  7. I’ve tried it and as you say, it ain’t impressive, but…I have this idea of closing in 3 sides of my circa 1960s small dining table with heavy cardboard and use the heater with 2 clay pots and the bread loaf pan. I hope that it will heat the small space and the heat will dump out into my lap, so to speak.

  8. I live in Upper Michigan in a 20×25 log cabin I built. I burn wood but always looking for alternative heat sources I tried this. I built a 4’x4’x6′ box with card board. I got 2 6″ clay pots and hardware a candle in a jar and placed everything in my living room. Shut heat down, I placed blanket and pillow in box also, it was 7° last night and I stayed warm all night..

  9. ive hot a lot of clay pots that have been collected over the years. Many bolts, washer and nuts. I think I will construct 6 of these and try them out ony 6×8 greenhouse. Will put a wireless remote thermometer to check the temp. Maybe it will keep my winter veges and plants warm enough to survive the coldest temp in the central valleu of California .

    • My mother uses this in her green house. Out side temp was 30 degrees Fahrenheit inside was 60 degrees in the morning. So it worked for her. Green house is 8×12 by 10 feet tall at the peak.

  10. Ive used several of these as aux heaters for my cold frames and we are still getting our lettuce from the cold frames.we have been lucky enough to seal and insulate our home built in the early 8o’s and with the oil lamps we use for ambiant light at night, have really cut out utilites. with energy cost looking like they will continue to increase in the long run thanks to the liberal agenda. thses will help in specialized applications.

        • Learn to get news from sources other than Brietbart. 30 seconds of research will tell you how much Texas gets from green/renewable sources (hint: about 10%) and what has caused the current outages (hint: failure to winterize gas lines and such).

          Education is power.

        • Yeah. If you don’t pay to maintain your electrical grid, it’s not going to work in incliment weather. Why are we blaming renewables for a private Californian utility killing people last summer and a private Texan utility killing people now? How did renewables make profiteers squander and/or possibly extort the funds intended for maintaining the grid in both places? Or did you not know about the concurrent natural gas shortage in Texas, or that the majority of the failure in the grid was from non-renewable energy?

    • You idiot! Liberals are the ones who are trying to lower costs with solar and wind power. It is the rich republicans who want to keep us tied to gas and coal forever!! Do your research before you spout off about something you obviously know nothing about. Did you see the power bills in Texas???? What are you just plain stupid? For God’s sake, use your brain. And stop making everything about politics, How about we just try to help each other instead of fight with each other?

  11. We had a power outage during the November blizzard in Maine.
    My daughter put blankets up over windows and door in one room and heated it with multiple candles. It was quite cozy. I think this would work in an emergency and even harness the heat. Am going to try this week end here in TN when the artic front comes through here to suplement my propane heat.

    • I live in TN also and I’d like to know how it worked for someone who actually built and used it. We didn’t lose our electricity but my cousin did for about 48 hours. This would also be a great addition to an emergency car kit if it works. Thanks!

  12. These heaters can be VERY dangerous. The enclosure around the flame captures the heat and radiates it back at the candle. I made one of these out of tea lights and took regular reading with my FLIR i7 and within 15 minutes it combusted. My research would reveal that the ignition temperature of the wax was around 230 degrees C. The flame itself exceed the capacity of the camera around 270 deg C (519 F). Once the wax ignited the heat output increased substantially.

    I also found a video online of a guy who almost burned his boat down with one of these. I would consider this set up for an emergency situation only and to be supervised at all times with a fire extinguisher nearby.

    • I saw the same video of the guy with the boat. He CLEARLY stated he used too many tea lights, the melted wax “ran over”, pooled in the dish below and ignited! Urged viewers to use ONE tea light, as instructed.

  13. They work well. Be safe, use a fireproof tray and use your brain. Great in a pinch, grand under a large table to keep warm when dining.

  14. I am using one in my truck. I have not used the bolts just two pots and six candles and I have the candles in a mudding tin so they don’t spill or tip over. I am a Security Officer and sit in my truck all night. I am trying to perfect the the system.

  15. 1 tea candle creates approximately 300 btu (MAX) no matter how you capture the heat it’s the same amount of energy. so if 300 btu’s of electric heat will heat the room then so will the candle.

  16. what kind of metal must the screw be?
    normal iron screw with galvanized paint over it or should be
    inox / stainless steel for plumbing ???

  17. I am just reading this whole thread. I have a friend whose landlord doesn’t use heat at all. she’s freezing at home. I’m trying this out as I sit in my COLD garage. I have a $2 pot in an aluminium tray next to one foot. (three tea lights) and that foot is warmer than the other. so it might help a person. Definitely more than just candles only.
    more to be revealed

  18. I made two heaters with slight variation of structure. The room had too much draft for it to be very efficient. i used a shallow cake pan, wire rack, tea light candles and two pots with bolt, nuts, washers. I will use it in my bedroom only, and think one will warm the space nicely for a few hours.

  19. I live in central Iowa I have been reading all the post and I am going to try to do something similar I will let you know what I think it does

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