Written by 2:42 pmSurvival

How to Build a Clay Pot Heater

Photo of hands on a pottery wheel

Did you know it’s possible to heat an entire room, with a few plant pots, bolts and a couple of tea lights? As winter is coming round again, you need to have some back up heaters ready for those cold and long nights, when your radiators aren’t working, and your house is slowly becoming uninhabitable. A clay pot heater is definitely a great option for some emergency warmth.

There’s no need to go and spend loads on a gas heater when you can construct a perfectly good flower pot heater all by yourself, using a few common household items. Not only are these heaters extremely effective, but are also really fun to make and are ideal for a family activity.

Read on to find out how to build your own clay heater. We’ll go over all the equipment you need, the construction method, and how to stay safe whilst you are operating your heater.

What is a Clay Pot Heater?

Clay pot heaters recently took the internet by storm, when a group of survival enthusiasts realised they could construct an effective heater out of flower pots and a few nuts and bolts. Terracotta clay is really good at retaining heat, and the pot heater makes use of this property by storing warmth in the clay, which is then transferred to the room around it.

The clay pot heater is built out of 3 pots, which are constructed so they have pockets of air between them. This air is also heated as the clay warms, which further improves the heat retention, and overall lets the heater put out even more warm goodness.

You might think that a heater this effective might be difficult to construct, but that really isn’t the case. As long as you’ve got the materials, you really can’t go wrong. It’s a fun and creative task to do as a family, but is also ideal for anyone who wants to hone their survival skills and get prepared for any turns in the weather!

How to Choose Materials

The first step in building an effective pot heater is to choose your building materials wisely. Like anything, what you get out is only as good as what you put in, so always try to use the highest quality materials you can find. This will ensure that you get enough heat out of your pot to warm a small room with ease.


The first thing you’ll need is a candle. A Tea light will work well, but if you want your heater to be burning for a long time, you might prefer to use a larger wax candle. The most important thing to check is that the candle fits inside the smallest of your clay pots, which means the diameter of the pot needs to wider than the candles own diameter.

You don’t need to buy an expensive candle, as we said before a tea light work well. You can always swap out a candle when it runs out so don’t worry too much about your candle. The other building materials are much more important than this, and will determine how effectively your clay pot heater will be able to keep you warm.

Clay Pot

If we’re going to making a clay pot heater, then it’s fair to assume that we’ll be needing some clay pots. Terracotta pots can be found in nearly everyone’s home. If you don’t have any, don’t worry, they are easily obtainable from any garden centre and most DIY shops in the country.

Specifically, you need 3 terracotta pots. They all need to be different sizes, so that the smallest one fits into the next largest, and they both fit into the the largest pot. This is so that we can create a layered heating system, with air in between each layer. Doing this will ensure our clay pots retain as much of the candle heat as possible.

When choosing your terra cotta pots, make sure that they are completely plain, and don’t have any gloss or paints on the outside. Heating these coatings might cause harmful fumes to be released, and it’s difficult to say how they will react to the heat. Be sure to look out for those classic clay colored pots – these are the ones you want to use.

Other Construction Materials

As well as candles and clay pots, there are few other materials that you’ll need to build a flower pot heater. The first one is a long bolt. With the pots inside one another, the bolt should be long enough to reach from the base of the largest pot, right through to the opening on the smallest pot. The bolt holds the pots together, but also absorbs heat energy from the candles, that is then transferred to the pot layers.

You’ll also need around 12 washers that fit around the bolt. These washers fill in the space between the bases of each pot, so that the layered structure can be retained. Like the bolt itself, the washers will also heat up nicely, and keep the candle heater nice and warm.

Finally, you’ll need some nuts, to hold the washers and bolt in place. We’d also recommend that you find a couple of old bricks or rocks, that you can stand the pot heater on whilst its in use. This is so you can slide the candle underneath, and access it when it runs out. Make sure you can raise your heater high enough to fit and slide your candle underneath, you really don’t want to lift the heater up when it’s hot in order to access the candle!

How to Build the Clay Pot Heater

Now that we’ve got our materials together, it’s time to build our terra cotta pot heater. There has been some controversy online as to what the best way to build the heater is, but we think that the following method is the best at distributing heat and being easy to use. Having said that, feel free to experiment yourselves to see if you can improve the design any further – one of the best survival skills is to take a design and still be able to make it better.

The following is a simple step by step guide for you to follow, which should help you construct your very own terra cotta candle heater.

Step 1: Fit the bolt

The first step is to position the bolt correctly. Insert the bolt through the drainage hole in the largest flower pot, so that it is sticking up to the opening of the pot. Now, place a washer and then a nut onto the bolt on the outside of the pot, and tighten them so that the bolt is attached to the base.

Also put a washer and nut on the inside of the pot, and tighten them up loosely against the inside base. You don’t want this to be too tight, else it might crack the pot. Then chuck a few more washers onto the bolt, which will create space between the next pot.

Step 2: Attach the next pot

Now, take your second largest flower pot, and place inside the larger pot, passing the bolt through the drainage hole in the base. The washers should stop the pot touching the other one, which creates those lovely air pockets that retain loads of heat. Make sure that this pot doesn’t stick out past the first pot. If it does, remove a couple of the washers and slide it back on.

As you did with the first pot, slip another washer and nut onto the bolt and secure the second pot into place. You should now be able to lift the pots up as one structure, and then should both feel securely attached.

Put 3 or 4 more washers onto the bolt, and secure them with a nut.

Step 3: Attach the final pot

Next, slide the third and smallest pot onto the bolt. Again, make sure that this pot doesn’t stick out past the others. You want the smallest to be inside the next pot, and those two pots to be well within the biggest pot.

Secure the small flower pot using a washer and bolt. Now you should have all three of your pots connected to one another, and everything should feel solid when you pick it up.

Congratulations, you’ve built a flower pot candle heater! Now all you need to do is set it up correctly and position your candle, as the next steps will explain.

Step 4: Set up the heater

Place your heater on your bricks or rocks, so that it balances and isn’t going to topple over. We’d recommend using three bricks, placed in a triangular layout, as this will provide the best stabilisation. However, you’ll have to make this work with whatever you are using.

Also, make sure to choose the location of your heater wisely. You’ll usually want it in the centre of a room, well away from any potential fire hazards. t’s also best to heat a small room from the centre anyway, and create convection currents around the whole space.

Step 5: Position the candle

If you’re ready to get your heater going, and have positioned the pots in a suitable location, then it’s time to light your candle. Once lit, slide the candle under the heater. Now you’re good to go. It shouldn’t take too long before you start feeling some heat coming off the pots. Be sure to keep an eye on the candle, and have a stock of tea lights ready to replace it with when it runs out.

Top Safety Tips to Remember

Although plant pot heaters are really fun to make and use, there a few things you need to consider when using one, to make sure that you are staying safe. Open flames always present safety issues, but if you are careful then there’s no reason why you should get into any trouble.

Here are a few things to be wary of, and some tips to remember in order to stay safe with your candle heater.

Carbon Monoxide

Carbon monoxide is a very harmful gas that is released when something is burning. It can poison humans very quickly, and can cause some very nasty complications. To prevent this from happening, make sure the room that the heater is in a spacious area. You don’t want to be locking yourself into a cupboard with one of these heaters for example.

You should never go to sleep with the heater burning. Not only is this a major fire risk, but this is the most common way people end up with carbon monoxide poisoning. The gas can slowly suffocate people in their sleep, without them even knowing. Just remember to blow out the tea lights before you call it a night.


Make sure your room is well ventilated before lighting your heater. Again, this will prevent any harmful gases from collecting in the room, and will reduce the chance of a fire. Ideally, you will use the heater outdoors, and then you won’t have to worry about ventilation at all. If you do need the heater inside, then make sure to remember to ventilate the room.

Don’t Leave Unattended

Never leave a tea light heater unattended. It goes without saying that you should never leave a naked flame alone, and this is absolutely the same with the heater. Anything could happen when you leave the room. If you need to leave the room, there’s no harm in sliding the candle out, snuffing it, and then relighting it when you return. Thanks to the heater’s design, doing this won’t mean that you lose loads of heat.


Do clay pot heaters work?

There have been plenty of arguments online as to whether tea light heaters work or not. In our experience thy absolutely do work, and if you follow our design steps, you’ll have a good chance of creating a working pot heater.

How do you heat a room with a clay pot?

The best way to heat a room is to place your clay pot heater right in the centre of it. This way, you’ll create some nice convection currents around the room, which will pass heat to all 4 corners.

How much heat can a clay pot take?

A clay pot can take loads of heat, so there’s no need to worry about your candle melting it. Terracotta is often used for high end cooking equipment, so is designed to withstand high levels of heat.

Does terracotta retain heat?

More importantly than being able to withstand heat, terracotta is also an excellent retainer of heat. It is this property that makes it absolutely ideal for our clay pot heater design.

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