Smoldering Fire

11 Reasons Why Your Wood Burning Stove Isn’t Getting Hot

In Indoor Fireplaces, Multi Fuel Stoves, Wood Burning Stoves by James O'KellyLeave a Comment

There are many different things that need to come together to have a successful fire in a wood stove, and so if you’re finding that your wood burning stove isn’t getting hot then there can be a number of reasons why.

So why is my wood stove not getting hot?

Reasons why your wood burning stove isn’t getting hot can include:

  • The draft on the stove is poor
  • Air vents aren’t open enough
  • The vents are open too much
  • Secondary combustion isn’t occurring
  • Building and lighting the fire incorrectly
  • The wood isn’t dry enough
  • The wood is cold
  • Not Using hardwood logs
  • The fire is too small for the size of the stove
  • The house is too airtight
  • The ash is being cleared out

I’ve discussed in more detail below why a wood stove wouldn’t be getting hot, and what we do to make sure we have the hottest and most efficient fires possible in our wood burning stove.

Why Is My Wood Stove Not Getting Hot?

1. The Draft On The Stove Is Poor

Sufficient draw on the stove from the flue is required to suck air from the stove and out of your home. This process also helps to pull fresh air into the stove and feeds more oxygen to the fire to help keep it going.

If there is insufficient draft on a wood stove then this can prevent your stove from getting hot. If waste gases can’t escape your stove, then fresh air won’t be getting to the fire and the stove won’t be heating up.

Every fireplace, flue and chimney situation is different. Some homes will have more draw on the fireplace than others, and can be affected by a number of things including how high the chimney is, how far it extends above the house, and the diameter of the flue in relation to the stove.

Even though these things can’t easily be changed, there are a few things you can do before each fire to start or improve the draft on the stove. Ensuring that the draw on the stove is maximized will help the fire to get going and heat up much more quickly after being lit.

Wood stoves are enclosed systems, and no air can get into the stove from your home if the door and air vents are fully closed. Stoves are still connected to the outside via the flue, and so the air inside the stove or flue can be much colder than the air temperature of the room.

Cold air sinks and hot air rises, and any cold air trapped within your flue can prevent hot air from the fire from rising out of your home.

Before each fire we like to leave the stove door open for a while to help bring both the flue and wood stove nearer to room temperature.

Stove Glass Clean
Leaving the door open on your wood stove can help bring it up to room temperature before starting a fire

You can test whether there is enough draw on your stove before lighting a fire by taking a rolled up piece of newspaper that’s lit at one end and placing it under the flue outlet inside your stove.

A heat source can help warm up the flue and start the draft on the sove
If you see smoke rising up the flue then it should be fine to start a fire

If you can see the smoke from the newspaper disappearing up the stove then there should be no issues with draft when starting the fire. Leaving the heat source under the flue outlet inside your stove for a while longer will help to start the draft as the air inside the flue starts to warm up.

You can read my complete guide to warming up the flue of a wood burning stove here.

A flue that is dirty may also be causing poor draw on your stove, and in turn preventing your wood stove from getting hot. It’s recommended that chimneys and flues are cleaned at least once per year, and ideally just before the burning season.

A dirty flue can reduce t’s efficiency at pulling air from your stove, and in turn sucking fresh air into the stove to help keep the fire burning hotter.

2. The Air Vents Aren’t Open Enough

A fire needs oxygen to burn through the wood. A larger supply of oxygen to the fire through the air vents helps the fire to burn through the wood more quickly, and in turn produce more heat.

If your wood stove isn’t getting hot, try opening up the air vents on the stove to allow more oxygen to get to the fire.

If the air vents are closed, or closed by too much, then the fire will smolder and burn very slowly due to a lack of fresh air. A fire that is smoldering isn’t burning through the wood quickly and efficiently enough to be generating much heat.

Smoldering Fire
If your fire is smoldering then open up the air vents to help it get going to produce more heat

I’ve explained how to use the air vents on a wood burning stove to control a fire here.

3. The Air Vents Are Open By Too Much

If you’re finding that your wood stove isn’t getting hot even with the air vents fully open, then air vents that are too far open can also be a reason why a stove isn’t getting hot.

The air vents on a stove should always be fully open when lighting a fire. A fire needs as much oxygen as possible to get going as quickly as possible and to bring the stove up to operating temperature.

Once the fire has visibility caught hold of the wood, then the air vents can be closed down in stages as the fire progresses to ensure that too much air isn’t getting to the fire.

Wood Stove Closing Vent
Closing down the air vents cam actually help the stove to produce more heat

A wood burning stove with wide open air vents will cause the fire to burn rapidly through the wood. Although a decent amount of heat will be generated, it’s also very inefficient and you’ll be adding wood to the fire much more often.

Allowing more air to the fire to provide bigger and faster roaring flames doesn’t always necessarily mean that more heat is being produced.

The idea behind a wood stove is to control the airflow so that the wood is being burnt in a more controlled manner, and that the heat and waste gases don’t leave the stove too quickly.

By closing down the secondary air vent which supplies heat to above the fire (more about secondary air vents here), until the fire is burning calmly through the wood (without it smoldering), you can actually generate more heat from the stove through secondary combustion of waste gases.

4. Secondary Combustion Isn’t Occurring

Secondary combustion, also known as secondary burn, is the process of burning off waste gases from the fire to produce even more heat from burning wood.

Many wood stoves will have this function to maximize the efficiency of burning wood, ensuring that as much heat is produced from every piece of wood used on the fire.

In many wood stoves the majority of the heat generated can be from this secondary combustion process. By keeping waste gases from the fire inside the firebox for longer, and at higher temperatures and pressures, they can be burnt to produce even more heat.

I’ve explained in more detail here how a wood burning stove works.

Secondary combustion typically only works at higher temperatures, and so you’ll need to ensure that you’re getting the fire up to operating temperature as quickly as possible by building and lighting the fire correctly, and by building up the fire with progressively larger sized logs.

A stove thermometer can be used to show what temperature your stove is really operating at. One thermometer located on your stove and one located on your stovepipe, can help you to understand how your stove is performing and why it may not be getting hot.

Stove Thermometer
A stove thermometer can you help you understand how well your stove is operating

There is an optimum temperature range where the wood is burning the most efficient, but isn’t generating the most amount of heat. For the stove to be generating large amounts of heat, the fire would need to be rapidly burning through the wood, but you’ll be adding more wood to the fire much more often as a result.

You can read more about secondary combustion in wood stoves here.

5. Building And Lighting The Fire Incorrectly

The aim when building and lighting a fire inside a wood burning stove is to help get the fire going as quickly as possible, so that a hot bed of coals can be produced, and temperatures and conditions allow for larger sized pieces of wood to be added to the fire without smothering it.

A fire that struggles during its early stages can prevent the stove from getting hot.

To help spread the fire quickly to the wood, we like to lay a bed of crunched up pieces of newspaper at the bed of the stove.

We then lay small bits of softwood kindling on top of the newspaper in a crisscross pattern to allow air to get in between. Softwood catches alight and burns more quickly then hardwood and so is ideal for use at this stage of a fire.

Lighting the newspaper at various points helps to spread the fire to the wood more quickly. Once the fire is rapidly burning through the initial bits of wood, smaller sized logs can be added to the fire to help increase the temperature of the stove.

Be sure not to use larger logs at this stage of a fire as they will struggle to catch alight due to their size, and can prevent your wood stove from getting hot.

You can read here how to build and light a fire in a wood burning stove to help get it hot quickly.

6. The Wood Isn’t Dry Enough

Wet wood can be a common reason why your wood burning stove isn’t getting hot.

Wood that is wetter than the recommended 20% or lower moisture content for firewood can prevent your wood stove from getting hot, because more energy from the fire is required to burn off the excess moisture before being able to produce heat.

The wetter the wood, the harder it is to catch alight and burn. When wood that is too wet is burnt, excess steam is produced by the fire, which in turn can also prevent the stove from getting hot.

You should therefore ensure that any wood being burnt in your wood burning stove is low in moisture content so that is can be burnt efficiently to produce heat.

Firewood that is ‘kiln dried’ or ‘well-seasoned’ is typically good enough to be used in a wood stove. A moisture meter will help you determine whether the wood is actually dry enough to burn efficiently. Look for wood that is around the 20% moisture content mark, but the lower the better.

If your wood is too wet then you’ll need to leave it to dry out (season) for a while longer.

You can read how we season our own firewood here.

7. The Wood Is Cold

Wood that is cold can make a difference in how well it burns on a fire compared to wood that is room temperature.

Much like how when wood is too wet, wood that is too cold is harder to burn on a fire because it takes more energy to bring the wood up to a combustible temperature.

We like to bring in wood from the outside a day before being used on a fire in our wood burning stove. This gives the wood plenty of time to warm up to room temperature before being burnt, and helps to ensure that we have a hot and successful fire.

Wood Storage
We keep the wood inside for a while before being used so that it isn’t too cold to produce heat efficiently

Therefore, to help get your wood stove hot, bring in any wood that is being stored outside or in a cold place in your home such as a garage so that it isn’t too cold when being used on a fire.

8. Not Using Hardwood Logs

If you’re burning softwood logs and you’re finding that your stove is not getting hot, try using hardwood logs instead.

Hardwoods such as Oak and Ash, are typically denser than softwoods such as Pine because they grow more slowly. The higher density of hardwoods helps to generate more heat from the same sized logs, and can help a fire to reach higher temperatures, and for your stove to put out more heat.

9. The Fire Is Too Small For The Size Of The Stove

The size of a wood burning stove installed in your home can be determined by the size of the room it needs to heat. If you have a large sized room, or want it to be able to heat the whole house, then a larger sized wood stove will be needed.

Building a fire that is too small for the size of the stove can prevent a wood stove from getting hot.

You will therefore need to ensure that you are building and maintaining the right size fire for your particular stove. Larger stoves will require bigger fires to operate as designed.

If you’re building fires too small in your wood stove, the remaining space inside the stove will be underutilized, and the stove may not be able to reach operating temperatures for procedures such as secondary combustion to occur.

Depending on the size of the logs, we maintain fires in our wood burning stove that are between 1-3 logs in size.

Try not to build fires too small for your stove or it can prevent it from getting hot

We also ensure that we’re not putting in too much wood that would cause the fire to be higher than the set of air vents located at the back of the stove.

Wood Stove Tertiary Air Vents
If you have any air vents located at the back of your stove then be sure not to build a fire higher then these vents

These air vents help to initiate secondary combustion, and so it’s important that these types of vents aren’t blocked so that the most amount of heat can be produced.

If your wood burning stove has these types of tertiary air vents (more about tertiary air in wood stoves here) be sure not to build your fires higher than these vents by not putting too much wood in the stove at any one time.

There’s also a limit as to how big you can build a fire in your stove without causing damage to it. Burning large amounts of wood can lead to over firing of the stove where the stove reaches temperatures that it wasn’t designed for. You can read more about over firing on wood stoves and how to prevent it here.

10. The House Is Too Airtight

We have a house that was built within the last couple of years and so as a result of modern technology and insulation, the house helps to keep the warmth in because there are very little drafts.

This can cause problems with air supply to wood burning stoves because air needs to be constantly supplied to the fire, or the stove won’t be able to get hot. If the house is too air tight then a vacuum effect can be created.

As a result, we need a vent in our living room (where the wood stove is located). This helps to ensure that there’s always a fresh supply of air to the stove and helps to keep the fire burning hot.

Fireplace Vent
Our vent ensures that enough fresh air is getting to the fire

If your wood burning stove isn’t getting hot and you don’t have an air vent in your home, try cracking open a window slightly as this may help to get your stove to produce more heat from a better supply of air.

11. The Ash Is Being Cleared Out

In many situations wood burns better when a fire has been built on a bed of ash inside the stove. As wood burns more efficiently with a supply of air from above the fire, a bed of ash won’t restrict any air from getting to the fire.

A layer of ash can help to insulate the fire and help it to burn through the wood more effectively. You can read more about how much ash you should leave in your stove here.

If your wood stove is not getting hot, try to leave a bed of ash that’s a couple of inches deep in your stove between each fire.

Further Reading

How To Get More Heat From Your Wood Burning Stove

How A Wood Burning Stove Works

Parts Of A Wood Burning Stove Explained

How To Use A Wood Burning Stove

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