How to check seals

Oven seal - replace the chimney seal. What you should know - or should pay attention to when changing a furnace seal:

Oven seal - renew - table of contents

Oven seal in the inspection flap on the exhaust pipe

Oven seals and chimney seals should be checked for heart and kidney at regular intervals. The seals not only have the task of preventing dangerous gases from entering the living space, because the air supply can also be increased if the furnace seals are defective. This means that the air supply can no longer be regulated as usual. The additional air that flows into the firing area at the defective furnace seal creates more heat and your items burn faster. It doesn't always have to be the seal on the fireplace door! Some ovens have extra seals, e.g. B. in the area of ​​the ash pan or the disc. Many exhaust pipes also have seals on the inspection flaps. These oven seals also lose their effectiveness over time as they slowly begin to decompose depending on the heat and age. The transition between the stove pipe and the chimney is also sealed with a stove seal. Even if you have a little more work to do in this case, you should also check the function of this chimney seal.

How do I recognize a defective furnace seal?


Check and replace defective furnace seal - chimney seal yourself

There are several options here. As described above, it could be that, despite the strongest throttling of the air supply, your firing material burns faster than usual. At the latest, however, when you can feel a smell of smoke or even smoke is already escaping when the oven door is closed. But even the initial wear can easily be determined. When closing the oven door, pay attention to how much force you have to use. If the handle can only be closed with very slight resistance, this is a sign of a worn oven door seal. You can also tell from the soot streaks whether the furnace is tight. Open the oven door and see if the soot has been trapped inside the oven seal. If you find more soot outside the seal, this is also a sign that the chimney seal is not properly sealing.

Defective furnace seal, visible soot streaks.



What types of oven seals are there?

Different types are offered depending on the type of furnace or manufacturer. Which is right for you mostly depends on the place of use. Some manufacturers only use flat seals for their glass pane seals. Other manufacturers but also oven sealing cord. So before you start ordering material, first check what types of oven gaskets you will need. Also make sure that several types of gaskets can be installed in an oven, i.e. both oven sealing cord and oven gasket flat.

How long does it take to replace a furnace seal?

Depending on which type of sealing cord you use, which adhesive or which oven seal you replace, you can assume an average of approx. 20 - 30 minutes. Then, depending on the manufacturer's instructions, the adhesives used must still dry. It is therefore advisable to replace the furnace seal before the start of the heating season. But this is only a recommendation! You can of course do this at any time. But who would like to go without their stove for a whole day in the dead of winter, depending on the type of adhesive?

What to look out for before buying an oven gasket!

Every manufacturer includes an instruction manual with their device! As a rule, you can also easily find the type or size of the seal you require here. If these operating instructions are no longer available, take a look at the manufacturer's website, where the operating instructions and technical data are usually available for download in PDF format. If you still do not have the required data, call the manufacturer! But if everything doesn't work, you have to do it yourself. Most window seals today use flat, self-adhesive seals. Here it is relatively easy to measure how wide the tape has to be with a folding rule. On average, these are all between 10 mm to 20 mm wide and about 2 mm thick. With round seals (also called sealing cord, sealing cord or also called oven seal) this is a little more difficult. You could measure the diameter of the defective furnace seal with a caliper, but since it is a defective furnace seal, the original diameter can no longer be measured correctly because the seal loses its circumference over time and thus a defect occurs.

How do you measure the diameter or how thick a furnace gasket has to be?


Measure the diameter of the furnace seal.
© - qimono

After you have removed the old, defective stove seal on the chimney, you can see how the guide-holding groove in which the seal is inserted - glued. If you now add the width and depth of this "groove" and then add another 2 mm, you have found the right diameter for your chimney seal. You can easily determine the length based on the length of the old seal or the circumference of the Fürhungs retaining groove. DANGER! Even in the unlikely event that two 1 meter pieces should be cheaper, you should still buy a 2 meter cord if necessary. Any denomination of the furnace sealing cord also has a negative effect on the sealing behavior and thus on the performance of your furnace. (Basically we are talking about amounts between approx. 8 - 20 euros, because one or the other euro should be saved in a less vital place.)


What to look for in the quality of furnace seals?

In principle, furnace seals of all kinds must be free of asbestos! Furthermore, you should use fiberglass sealing cords if possible, as these are usually resistant to oils, fats, organic acids and solvents. On the right side of this homepage you will find a selection of the most commonly used seals. There you will also find recommendations for the stove and chimney seal you need.

Buy furnace seals directly online with no ifs or buts!

On the right-hand side in the seal overview section you will find recommendations for all types of seals around the stove - fireplace. Basically, we recommend buying from Amazon because the return costs are also covered in the event of a return and Amazon is generally very accommodating. In addition, Amazon itself always has a very high availability of all required seals. Especially when you need different seals or adhesives, you can always get everything at once. And thanks to Amazon Prime, the delivery time is always very fast and usually the next day, even without it.

Renew / change furnace seal. Step by step

So can your Replace the furnace seal.
1. Your fireplace should not be fired before, during or after the entire working day. This applies until the point in time when the manufacturer specifies the hardening process of the adhesive.
2. DANGER ! In very old ovens, oven seals may still contain asbestos! In such a case, you must absolutely wear a protective mask / protective clothing because the asbestos is highly carcinogenic!
3. First remove the old seal. Now, as already mentioned above, the so-called guide holding groove appears. There will probably still be residues of the adhesive in this after removal.
4. Remove any remaining adhesive, ideally with a Phillips screwdriver. This is very important so that later no unevenness forms which in turn could make the sealing cord permeable.
5. Now open the package with your new seal and read the package insert carefully. Some manufacturers recommend applying the adhesive only selectively, others recommend applying the adhesive continuously. In any case, follow the instructions. If you are working selectively, place as many adhesive points as necessary until the tube is empty. Be careful not to apply the glue dots too thickly. Otherwise, when the sealing cord is attached, glue can escape from the sides of the sealing cord.
6. Start You now on one of the two lowerCorners (This means that no smoke can escape upwards at the seal transition) and press the cord firmly into the guide retaining groove with your fingers only. Never use a screwdriver or any other sharp, pointed tool to press the sealing cord into the holding groove so that no cuts or erasure can occur. Pay particular attention to the transitions (every following corner) that the furnace seal does not twist. Shortly before the seal is finished, hold the sealing cord loosely in front of the end and take measurements to shorten it to the correct length. It is best to try to cut the sealing cord with a sharp knife so that the end does not fray. A helpful third or fourth hand can really help. Now carefully press in the rest of the way, evenly until the end. There must not be a gap later (cut too short), nor must the beginning and end overlap significantly, as this would prevent the door from being properly closed later and thus the seal in other places becoming unusable again.
7. Now pay attention to the drying times specified by the manufacturer in the package insert. If you have worked properly and no glue has escaped from the sides of the sealing cord, you can close the oven door during the drying time. At least now you will notice that the door is more difficult to close again. This is because the old seal was worn out and no longer built up enough pressure to make the door really tight. (It will be easier again in a few years.)

!Danger! *** Smoke alarms warn too late ***! ATTENTION!


90% of all burnt offerings to dieat one Smoke poisoning and not on the flames!


Additionally A smoke alarm should be on every fireplace in the house CO alarm be attached.


(Meanwhile too without drilling possible)



If you haven't even installed a smoke detector yet, you can also opt directly for a combination device.


X-Sense DS51 Combined CO detector Carbon monoxide detector and smoke detector, battery operated *
  • advanced technology: superb intelligent MCU processing technology with a dual sensor detects dangerous levels of both smoke and carbon monoxide; surface mounted technology (smt) ensures better mechanical performance
  • superior performance: delivers a sound of 85 db to alert you to the presence of smoke and / or carbon monoxide; shields interference from external light in order to maintain the function of the photoelectric sensor
  • Multifunctional: you easily press the silent button to stop any false positives; the detector automatically returns to standby mode after the spread of smoke and / or the risk of carbon monoxide; a self-diagnosis function shows possible malfunctions with a flashing yellow LED and a warning tone
  • Dustproof, moth proof able to withstand shocks, and easily fits into any space vehicle
  • Reliable power supply: 2 AA batteries (included) with a 3-year lifespan ensure a reliable power source; a low voltage warning gives a reminder when battery replacement is required,

* Last update on May 18th, 2021 / Affiliate Links / Images from the Amazon Product Advertising API