Problems & Repairs
A stove that lights beautifully and then quietly dies twenty minutes later is one of the most annoying faults there is, partly because it feels like you are doing something wrong. Usually you are not doing anything unusual. Something has changed in the air supply, the fuel or the flue.
Work through it in the order below rather than jumping to conclusions, because the cheap causes are also the common ones.
First: are you closing the air down too early?
A fire needs to establish a bed of hot embers before it can survive on reduced air. Closing the primary air within a few minutes of lighting, which is a habit people pick up to save fuel, will kill a fire that had not properly caught yet.
Leave the air fully open until the logs are visibly charred all over and the flames are steady rather than flickering, then reduce gradually and watch what happens. If the flames go lazy and orange rather than lively, you have gone too far.
Second: the wood
Wet wood does not fail dramatically. It fails exactly like this, by lighting on the kindling and then refusing to sustain itself once the kindling burns away, because the energy of the fire is going into boiling water out of the log rather than into heat.
A moisture meter costs very little and settles the argument in seconds. Below twenty percent is what you want. Wood stored outdoors uncovered, or in a sealed shed with no airflow, will not get there no matter how long it sits.
- Split a log and test the fresh inner face, not the weathered outside
- Store off the ground, covered on top, open at the sides
- Kiln dried fuel is a reliable shortcut if your storage is poor
- Never burn painted, treated or reclaimed construction timber
Third: air getting into the room
A stove cannot pull air the room does not have. New windows, a sealed floor, a fitted kitchen with a powerful extractor, or a modern trickle vent taped over in winter will all quietly starve an appliance that used to work.
The test is simple. Open a window in the same room by a hand's width and light the fire again. If it behaves, the problem is air supply, and a permanent vent is the fix.
Fourth: the flue
A restricted flue produces exactly this symptom, because there is enough draw to get a small kindling fire going and not enough to sustain a proper burn. Soot narrowing the bore, tar, a nest, or debris sitting on a bend all do it.
So does a cold flue. An external stack in a Scottish winter can hold a plug of cold air heavy enough to stall a fire on lighting. Warming the flue with a taper first, and building the fire top down, both help. If the flue is uninsulated and permanently cold, lining it is what actually fixes it.
Fifth: the appliance
A perished door rope lets air in at the wrong point and disrupts the airwash and the burn pattern. A blocked or heavily ashed grate stops air reaching the fuel bed from below on a multifuel stove. A dislodged baffle plate short circuits the gas path through the firebox.
These are all things a service picks up, and they are cheap to put right compared with the fuel wasted fighting a fire that will not burn.
Frequently asked questions
Why does it burn fine and then die when I shut the door?
That points at air supply through the door rather than through the controls. Check the air controls are actually open, then check the rope seal, and consider whether the room has enough ventilation for the appliance.
Should I leave ash in the bottom of the stove?
On a wood burner a thin ash bed helps, because wood burns better on ash than on bare steel. On a multifuel stove burning on a grate, ash needs riddling out so air can reach the fuel from underneath.
Could the stove be too big for the room?
It can contribute. An oversized stove gets run shut down all evening to avoid overheating the room, and running shut down is what makes fires die and flues tar up. Sizing is worth getting right at the point of purchase.
When is this a sweep job rather than a technique job?
If the fire behaves with a window open and dry fuel, it is technique and ventilation. If it still dies with plenty of air and dry wood, the flue is the next thing to check and that is our end of it.
Fire still dying with dry wood and plenty of air?
Book a sweep and a stove check. We clear the flue, confirm the bore with a camera and look over the seals, grate and baffle in the same visit.