Why do I get a failed ignition on some start-ups?

A failed ignition can occur for a large number of reasons. However, you should always remember that fire is a simple concept. Fuel and oxygen are all that are required for a fire to burn successfully with an additional spark to get it going at the start.

All quality wood pellet stoves will need to hit certain targets during a start-up cycle, be it a flame size as determined by a photocell or a flue gas temperature as determined by a temperature sensor. It’s usually the case that these targets must be achieved within a certain timeframe also and if this time is exceeded, the stove will generate an alarm and initiate its shut-down cycle. This is normal and nothing to be concerned about.

Best practice in this situation is to clean out your burn pot, ensure that your ignition element (usually in a cylindrical tube at the rear of the burnpot) is clear of debris and dust and that the burnpot is seated correctly into position.

• A dirty burnpot – when the burnpot is dirty, many of the air holes will be blocked which reduces airflow through the pellets. Without adequate airflow, the pellets will be unable to ignite.
• Incorrectly positioned burnpot – it’s critical that the burnpot is correctly positioned. The large hole in the burnpot must align with the ignition element (usually at the rear of the burnpot) and the “shoulders” of the burnpot must seat neatly on to the frame on all sides. Ensure that no dust lies between the frame and the burnpot.
• Ignition element has moved or is incorrectly installed. The cylindrical tube that holds the ignition element should be very close to or touching the burnpot. The ignition element should be set back from this by at least 8mm but the distance will depend on your stove model and type of ignition element. If you’re unsure about yours being correct, please contact the store you purchased it from or, you can raise a ticket here.
• Faulty ignition element. Should everything else above be in order, it’s possible that the electric ignition element is faulty or has reached end of life. An operational ignition element should get very hot during the ignition cycle and glow bright orange.
• Pellets not dropping into the burnpot. If wood pellets are not dropping into the burnpot or if they’re dropping more slowly than usual, then there may be an issue with the feeding screw. The most normal issue in this regard is a foreign object stuck in the auger screw.
• Professional maintenance requirement - if your stove is starting to get dirty inside the flue passages, air flow will be affected. This can affect the speed and reliability of ignitions. 
• Lack of air supply – if anything is restricting the air supply to your stove or boiler, it may be unable to light or light quickly enough.
• Flue gas sensor dirty. If your stove is firing up quickly and appears to be working perfect but you still get an alarm, it may be an issue with your flue gas temperature sensor or photocell. This could be due to the sensor having become dislodged or dirty. The latter is more likely and if this is the cause, it usually indicates an immediate requirement for a professional service.

If you think all the above points are in order and that none of them are to blame for a failed ignition, then you should get a trained technician to look at your stove. You can raise a support ticket on this page or contact your installer or supplier directly. There is still plenty that can be done to make sure that your stove lights up reliably so don't despair. There are many stove settings, that are only available to trained technicians, that can be adjusted to improve efficiency and the reliability of ignitions. 

Note: Such changes should never be made by an inexperienced or untrained person as this could lead to a dangerous situation with your stove.