The expected lifespan of a door knob is somewhere between 4 – 10 years depending on how the fire is being operated.
The door handle will get hot during operation and this is completely normal.
There are two typical known causes of premature failure of the door knob. The first is excessive charring on the back of the knob due to high levels of concentrated heat from burning close behind the door area. The second cause can be due to the door being over-tightened when it is closed which in turn leads to it being very tight to open once the fire has heated up. The continued cycle of this over-tightening causes the screws to become weakened from the higher levels of load put on them in each direction each time, which eventually results in it coming loose and breaking away from their fixings.
A combination of these two is actually the most common cause of door knob failure. To avoid these issues and extend the lifespan of the door knob, keep a clear area of approximately 10cm in the front of the firebox and maintain your fire underneath the air tubes in the top of the cylinder, this will give the additional benefit of letting the cylinder absorb the maximum amount of heat from your fuel load before it leaves the fire chamber.
If you are finding the door knob too hot when trying to refuel your fire then you are probably trying to refuel too soon, the door knob is a great indicator of what’s happening within your fire so if you can’t reload then you don’t need to yet. If your door knob is starting to show signs of charring then you are probably burning your fire too close to the door.
Do not lean on the door or use it to help you stand up when it is open as this can cause the door to move. If your door does become misaligned then you will need to loosen the top bolt going horizontally through the hinge bar and lift the door back into the correct position for the spindle to line up and then re-tighten the bolt.