Operating instructions

Heatmax Furnace Installation and Operation Manual
23
4.3.5.4 Maximum burn cycle times
The burn cycle time is the period between loading wood on a coal bed and the
consumption of that wood back to a coal bed of the same size. The flaming phase of the
fire lasts for roughly the first half of the burn cycle and the second half is the coal bed
phase during which there is little or no flame. The length of burn you can expect from your
furnace, including both the flaming and coal bed phases, will be affected by a number of
things, such as:
• firebox size,
• the amount of wood loaded,
• the species of wood you burn,
• the wood moisture content,
• the size of the space to be heated,
• the climate zone you live in, and
• the time of year.
• the time cycle for the thermostat to call for heat.
The table below provides a very general indication of the maximum burn cycle times you
are likely to experience, based on firebox volume.
FIREBOX VOLUME
MAXIMUM
BURN TIME
<1.5 cubic feet 3 to 5 hours
1.5 c.f. to 2.0 c.f 5 to 6 hours
2.0 c.f. to 2.5 c.f. 6 to 8 hours
2.5 c.f. to 3.0 c.f. 8 to 9 hours
>3.0 c.f. 9 to 10 hours
4.4 The use of a thermometer
There are several factors favoring the use of a chimney thermometer. There are two types
of thermometers, magnetic thermometers and probe thermometers. The two types of
thermometers have the same advantage, magnetic thermometer is designed for single wall
pipe and the probe for double-wall pipes. The first use of a thermometer is to inform the
user about the discharge temperature of flue gases. The thermometer will indicate if the
temperature is ideal, too low or too high. Use the thermometer to better control the heat of
the furnace.
4.4.1 Safety
Too low temperatures, usually indicates that the fire is too low and the smoke is very
apparent, which increases the risk of accumulation of creosote in the pipe and thus
increases the risk of chimney fire.