Why is My Log Burner Leaking Water?

Considering log burners produce fire, it can be slightly worrying if you find water inside the stove or see water leaking out the top or sides.

So, if you’ve seen this happen, you’re probably asking, why is my log burner leaking water? There are numerous reasons why your log burner might be leaking water, although very few of them are serious issues. For example, it could be as simple as rain or condensation, or it could be that your boiler stove is leaking. Leaking water alone isn’t necessarily enough to diagnose the problem.

Below, we’ll cover the main reasons why your log burner might be leaking water. Hopefully, working through this list will help you narrow down the possible reasons.

Why is the Inside of My Wood Burning Stove Wet?

There are a couple of reasons why the inside of your wood burning stove is wet. These include:


The most obvious reason why there’s moisture inside your stove is that rainwater has managed to get down the chimney. It’s fairly common for this to happen, although it obviously depends on the size, shape and angle of your chimney.

To avoid this issue, consider installing a chimney cowl. As you can probably guess, this is basically a little hood for your chimney, which prevents rainwater from dripping down into your stove.


Surprisingly, condensation can be an issue inside a wood burning stove. It can happen if your stove isn’t working hard enough. If this is the case, the stove and surrounding equipment won’t get hot enough.

This can cause flue gases to cool inside the flue, causing condensation that can drip down into your stove.

The simple fix to this is to ensure your stove is burning properly – consider fitting a thermostat and having enough airflow so wood burns at an appropriate rate.

Why is My Log Burner Leaking Water?

Burning the Wrong Wood

The wrong wood can mean various things. If you’re experiencing water in your log burner, the most obvious wrong type of wood is improperly seasoned wood. Seasoning is meant to reduce the water content.

Unsurprisingly, if it hasn’t been seasoned long enough, you might find this excess water evaporates and condenses inside the flue.

Another issue is wood that’s been properly seasoned but has a higher moisture content than average. For example, most types of pine and larch can produce lots more tar than drier wood. In turn, this can create very wet tar residue inside your stove.

Reasons Why Wood Burner is Leaking Water

Similarly, if your wood burning stove is leaking water, it could be due to the following:

Poorly Sealed Joints

If the joints between your stove and flue, or stove and water boiler, aren’t sealed properly, water can leak out. Depending on the product used, some can deteriorate over time. Consider getting a professional in to take a look, or remove the product and re-seal it if you feel confident doing so.

Wrong Boiler-to-Stove Ratio

Not many of us have boiler stoves, but they can be a common culprit when it comes to water leaks. One of the more common issues is when your stove is too small for the size of boiler you’ve got installed.

Specifically, if the heat output isn’t high enough to heat the required amount of water, it reduces the burning rate.

Similar to the wood issues mentioned above, this can lead to condensation within the heating system. You’ll find this water either inside the burner or possibly leaking from the pipes.

Lighting Your Stove

It’s not uncommon for moisture to appear in your boiler stove shortly after lighting it. This is because the air within the boiler stove system can be damp. It gets warmed by the new fire and hits the cold walls of the boiler, causing condensation.

Luckily, it should disappear fairly quickly after lighting the fire.

Temperature Issues

Many of these reasons come down to temperature issues. These could be because of the wood you’re burning, the size of your wood burner, or even issues with your thermostat.

Provided the system itself is properly sealed, it’s likely a temperature issue is the reason for the leak.

It’ll also be worth checking the thermostats on your system. If any are set to 40 degrees or below, it might not be allowing the system to operate at the correct temperature.

Check your thermostats on the boiler and stove system and increase their temperatures if needed.

Log Burner Leaking Water

Water leaking from your log burner can be worrying, but it’s often a fairly easy problem to diagnose.

However, if you’ve been through the list above and can’t find an issue, it’ll be worth calling in an engineer to take a look. After all, water leaks should never be left alone!

log burner leaking water