FAQ - Frequently Asked Questions

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The stove doesn’t burn effectively

Is your stove equipped with an air supply? If yes, it needs to be checked if the register is opened completely. If no, you can try if you get a better performance by removing the small blind below the stove. The stove the gets 40% more air and thus should burn a lot better. Please also check the tuner lever. t has to be open completeyl (Tuner is standing vertical and back to the stoves end. Please also check with your retailer.

Another tip: Check if your stove burns better if your windows are open / tilted.

Stove doesn’t work in TwinFire mode / fire tube soots

  1. Switch to TwinFire is done too early (see also “Door glass soots”).
  2. The sealing in front of the stove may be damaged. Thus, air from the room is sucked into the stove and is burned uncontrolled. The uncontrolled supply of air develops grime. The sealings (front and top) need to be exchanged. Please ask your retailer for your help.
  3. The pressure in the chimney is too low.
  4. The chimney collar is lying in dynamic pressure area or is blocked by surrounding buildings.
  5. More heating appliances are connected to the chimney and effect a malfunction of the system chimney / stove.
  6. Wood with a high moisture is used.
  7. Heating is done with a low temperature.

Door glass is getting white / milky

Door glass is getting white if the stove is fired with a very high temperature (above 750 C°). These high temperatures overcharge the stove. There may be too much air in the combustion process. Too much air is sucked in the stove if the pressure of the chimney is too high (more than 12Pa). There have been high pressures of around 30 Pa experienced by us. To avoid this a limiter can be pur in the chimney. It has to be clarified with the chimney sweeper where exactly the limiter can be placed. Check the holes in the double bottom, these may have to be cleaned. Please also check if the air baffle plate in the lower chamber is fit in correctly and not closes the air slots.

The milky white surface can’t be cleaned anymore and has to be exchanged.

Door glass sooty / black

If the door glass is getting black or dusty (mostly in the lower part) too much of the exhaust gases aren’t burnt up properly. These gases will then cumulate on the coldest part (door glass). In most cases, this occurs if the stove is switched to TwinFire mode too early. This means the temperature around the TwinFire rust is too low to ignite all exhaust gases. Depending on the chimney and its draft the moment of switching may strongly differ. Just have a look at the rust. If it starts glowing, you can switch to TwinFire. Another indication for having established a temperature high enough are the stones in the upper chamber. If they have been “cleaned” by the flames and are free of dust and ashes, temperature should be high enough for TwinFire mode. The amount of blaze also must be high enough, recommended is a thickness of at least 2cm.

Clean door glass from grime

Since our stoves burn all exhaust gases, sooting should not apply. If it nevertheless occurs (due to false treatment / adjustment), it has to be removed. The deposit can only be removed by burning. Ashes will not work in this case, chemical cleaners shouldn’t be used to protect the door glass. Small traces of grime and ashes can be removed easily. Use some smooth crepe paper, moistened and put it in the ashes to ingest some ashes. The glass then can be cleaned by using the ash covered crepe. Afterwards, clean the rest with a moist crepe without ashes.

Vermiculite have tears

Vermiculite are wear parts that can be torn due to the immense heat in the firespace. The tears in the stones come into being by movement of stoves‘ body. They aren’t problematic as the stones do not have any static effect. They are solely for protection of the body. Tears in the stones do not have any effect of the stove, they are an optical problem. Spare stones can be bought at your specialist retailer. The stone sides of the upper chamber can be changed from left side to the right side, thus the stones can be used longer.

Vermiculite crumble

This occurs if soft wood is used, soft wood with a high residual moisture is even more problematic. Soft wood is not approved for usage within a xeoos stove. Soft wood produces a lot of ashes and salts. The salts will melt due to the high temperatures and built up scoria. The scoria will start to dissolve the stones within the stove. Soft wood, which is causing this, are for example poplar and spruce.

To avoid this, we recommend using hard wood in the stove only, best wood is beech tree wood. Please also check the manual for reccommendations concerning combustibles.

It is recommended to leave parts of ashes in the stove to able to get the fire started quicker, but the chambers should be cleaned up after a week in order to prevent causing harm on the vermiculite stones.

Wir empfehlen zwar, die Asche im oberen Brennraum zu belassen, da diese katalytisch beim Entzünden des neuen Brandes wirkt, aber länger als eine Woche bei täglicher Nutzung sollte man den oberen Brennraum nicht mit Aschresten gefüllt lassen.

Double bottom is torn

The double bottom separates the upper from the lower firespace. In the middle, there is a hole where the fire rust is placed. It is possible for the double bottom to tear at the edge of the hole. This is caused by heat expansion and thermal stress of the material and is directly dependent on the usage of the stove. Tears in the double do not have an impact on the thermal output or the function of the stove and are simply a visible problem. Maybe your chimney produces a too high air draft, please do check this with your chimney sweeper.

The double bottom is an expendable part and can be ordered at your specialist retailer.

Stone sides are torn

Our stoves are encased with natural stones, which usually show little differences in colour and appearance, thus also in density. Due to thermal expansion during heating, the stones can break or tear. Lava stone is most likely to tear as it has a very porose structure.

The pores and cavities within the stones have no effect on the function of the stove. These are just optical differences.

To avoid tearing: Keep an eye on the heat of the stove.

Stainless steel door discolours / spoils

If the door starts to discolour, the stove may be burned too hot. The discolouring tends to happen if the lower firespace is too hot. This is caused by a too high draft of the chimney. The discolouring of the door can’t be repaired completely, the door can be cleaned only with a special cleaner for stainless steel. Please always clean in the direction of the polish of the door. Most likely the steel will have discoloured due to the heat. To avoid the discolouring, the stove can either be choked (with a special blind or an air flow register) or the chimney draft can be lowered. This will avoid thermic overload. If your chimney has a draft which is too high, the stove can be damaged.

We recommend to measure the draft of the chimney. Draft should be 12 – 15 Pa.

Door spring torn

Mounting: The cover panel or the sides of the stove have to be removed. Then the spring should be visible and can be reached. The spring only is required if 2 or more stoves installed are using the same Chimney. If there is only one stove installed, the spring can be removed.


Usually, embossments in the door frame arise during the production process and aren’t a quality deficit. Technical background: unfortunately this is a manufacturing problem. The bolts can’t be welded vertically to the contact surface. To get an adequate consistency, we have to choose parameters that cause embossments. Small embossments thus are caused by production and indicate flawless welding with a high consistency.

Pop and crack sounds

As it is mentioned in the manual, these sounds are caused by the expansion and contraction of the body of the stove which are a result of the heat. The longer the stove is burned, these sounds can get louder due to the formation of bigger friction surface.

To reduce this, the xeoos is built with a vertical armature. The body itself thus can’t produce any crackling sounds.

If the pops are very loud and sound metallic, it may be possible that the isolation panel is the reason. The panel is located at the back of the stove and is attached with 4 screws. To loosen the screws a little may already stop the sounds.

Best would be to remove the panel and treat the bolts where the panel is fixed with a little bit of lube oil. This should stop the sounds completely. If they come back, just repeat the process.

Scratches on the varnish

We are producing stoves that reach temperatures of more than 500 °C in the firespaces. Due to this, only special varnishes can be used for production. We obtain our varnishes from a well-known german company. These varnishes have a clear focus on being heatresistant.

Of course we look for an adequate packaging when shipping the stoves. Nevertheless scratches sometimes can occur during transportation.

If you have any scratches on your stove, we can supply the varnish in cans.

Scratches in the varnish of the base frame of PUR stove

To avoid any scratches, some customers who bought a PUR years ago, use glass panel which are put on the bottom of the base frame to protect the varnish.

We are producing stoves that reach temperatures of more than 500 °C in the firespaces. Due to this, only special varnishes can be used for production. We obtain our varnishes from a well-known german company. These varnishes have a clear focus on being heatresistant.

The Body and all base frames are treated with Senotherm UHT 600 Varnish, quality 1155 which hasn’t to be burnt-in. The varnish drys out completely very fast, especially in rooms with an air moisture above normal. This varnish was chosen by us since it does not smell when burning the stove for the first times.

The U-formed base of the PUR stove will not heat up till 500 °C, but on top of the sides’ temperatures up to 300 °C are reached. Therefore, the same kind of varnish has to be used for the base frame as well. Main problem for stove varnishes is the thickness of the varnish brought up to the stove. If thickness exceeds 25 µ, the varnish tends to tear due to lack of flexibility.

The varnishes used by us are aligned to the thickness that is necessary. We understand that you are looking for a varnish that withstands tearing. Unfortunately, both technical aspects (necessary thickness vs. tear strength) cannot be realized.

AQUA does not deliver enough heat

The stove is burned too cold. T1 has to be at least 70 °C, to bring the fan in movement constantly and thus start the hot water delivery.

AQUA cable prolongation

To avoid disturbances, the cable should be kept as short as possible.

Why are xeoos stoves so expensive?

We are producing approximately 1000 stoves per annum in Reddighausen. We have about 12 models with up to 30 variants per model. Thus, we produce only order-related. We look at ourselves as manufacturer instead of an industrial producer. We are offering a fascinating and unique product, which is built individually. This approach has its price and you have to treat yourself for the stove.

When do I switch to TwinFire mode?

Have a look at the TwinFire rust. If it starts to glow red, the time is right to switch on the 2nd fire. Another indicator for having reached the necessary temperature are clean Vermiculite stones. If the flames have burned the dark spots on the stones away, the stove should be hot enough for switching to TwinFire mode. The amount of blaze has to be thick enough (should cover 2 cm of the bottom in the upper firespace).

It is absolutely necessary to have temperatures of about 1200 °C somewhere in the stove. This will be the case after preheating for at least 30 minutes. Give the stove and the chimney the necessary time to warm up the complete system. If it is really cold outside, it might be necessary to preheat up to 50 minutes to warm up the complete system.

Is it possible to place the chimney on top of stove?

If the chimney is mounted above the stove, only a short connection is allowed to be mounted to the stove. The complete weight of the chimney has to be carried by the ceiling. Our stoves are not built to carry additional weight.

For further questions, please contact your chimney sweeper.

What happens to the ashes in the chimney after it has been cleaned?

The ashes is going to fall in the stove. At the upper part of the stove is a collector for the exhaust gases which bottom is aligned horizontally. The ashes can be vacuum cleaned there. The company Raab offers chimney tubes with a cleaning port. Below the cleaning port but above the exhaust branch of the stove is a cleaning vessel, which can be removed. The chimney sweeper can install this device so that the ashes is going to land in the vessel. The vessel then can easily be vacuum cleaned or removed.

How do I clean the chimney tube?

We can’t unfortunately give you any hints concerning this issue. Cleaning of the tubes has either to be clarified with your chimney sweeper or the specialist who installed the stove.

We can only give instructions for the cleaning of the stoves. Please be advised that the cleaning of the stove has to be done after the stove has cooled down completely. (At least 40 hours after heating) and that the removal of the Vermiculite stones has to be done carefully, as the stones tend to break easily after having been in usage.

How often do I have to clean the stove?

The ash box has to be cleaned every 5 – 7 days. The lower firespace and the double bottom have to be cleaned once per burning season.

Can I install the stove if an air ventilating system is already installed? (Passive house)

In combination with an air ventilating system, the xeoos-stoves can be installed only in combination with a differential pressure switch. There can be situations during the operation of a ventilating system which can’t covered by a general certificate. Thus, we recommend a safety circuit and the usage of an external air supply. A permission for open flue operating is not needed then. Please also ask the appropriate chimney sweeper about this topic.

Can the stove be operated with pellets, wood briquettes or stone coal briquettes?

Our stoves can be operated with wood, wood briquettes and brown coal briquettes. But not with stone coal (Stone coal would be too hot) and not with pellets (these would fall in the lower firespace).