page 11
www.jayline.co.nz
NOVEMBER 2016
Correctly installed and operated, Jayline solid fuel heaters do not spill smoke into the house. There are
three main reasons why some woodstoves smoke:
Bad installation design: Incorrect fl ue installation, resulting in low fl ue temperatures and low draught,
can make a wood heater more likely to spill smoke. For example, each elbow in the fl ue pipe assembly
slows down the fl ow of gases and causes a small restriction to fl ow. When a fl ue system includes more
than one elbow, the restriction can be enough to cause spillage.
Extreme negative pressure in the house: Energy effi ciency practices and new building code rules are
making our houses more and more airtight. This makes the houses energy effi cient, but also makes them
more sensitive to negative pressure when air is exhausted from the house. Large, fan-forced exhaust
ventilators, like down-draught-type kitchen stove exhausts, can cause extreme negative pressure in
the house when they are operating. Because new houses are tightly sealed, there are few holes to
allow replacement air to enter, and the house pressure becomes negative. This negative pressure works
against fl ue system draught. In severe cases, the negative pressure in the house overcomes the fl ue
system draught and the appliance begins to spill smoke, especially when a fi re is started or when it dies
down to coals. To prevent this extreme negative pressure, one option is to open a window slightly to
allow combustion air into the room.
Improper heater fi ring technique: When a solid fuel heater is starved for air it smoulders, producing a
relatively cool, smoky fi re. The temperatures throughout the system are low. During a smouldering fi re,
the fl ue system will not be receiving the hot gas it needs to produce strong draught. When the heater
door is opened, smoke will spill into the room. A smouldering fi re is the single most common reason for
smoke spillage and totally unnecessary. By using the suggestions on proper fi ring technique earlier in
this document, you will be able to avoid these smouldering fi res.
