CFM Corporation Winter Warm - Small Insert How To Build and Sustain a Wood Fire

How To Build and Sustain a Wood Fire

A WinterWarm Small Insert leaves the factory with the combustor installed.

In the United States, it is against the law to operate this wood heater in a manner inconsistent with operating instructions in this manual, or if the catalytic combustor is deactivated or removed.

High-Efficiency Wood Burning with

Catalytic Combustion

The components of the catalytic combustion system in your WinterWarm Small Insert work together to produce optimum conditions for secondary combustion.

When the damper is closed, smoke is directed through the catalytic element, which causes ignition of smoke at temperatures of 450°-550°F (230°-290°C), half the temperature normally required for unaided secondary combustion.

The catalytic element is a ceramic “honeycomb” coated with the catalytic material. The element is located in the secondary combustion chamber, molded from a special high-temperature insulating refractory mate- rial. The design of the chamber provides the correct environment necessary for secondary combustion of the fuel (smoke).

Catalytic combustion is activated by closing the damp- er, thereby exposing the smoke to the combustor.

Closing the stove damper may also reduce the draft, so to avoid putting out the fire or deactivating the combus- tor, close the damper only when a fire is well-estab- lished. When starting a fire, wait until the fire is well established and there is an ember bed of at least 3-4” (76 - 102mm) before closing the damper.

Never kindle a fire with colored paper or paper that has colored ink or a glossy surface, and never burn treated wood, garbage, solvents, or trash. All of these may poison the catalyst and prevent it from operating properly. Never burn cardboard or loose paper except for kindling purposes. Never burn coal; doing so can produce soot or large flakes of char or fly ash that can coat the combustor and cause smoke to spill into the room. Coal smoke also can poison the catalyst so that it won’t operate properly.

In general, the fire must be sufficiently well-established to ensure that catalytic activity is initiated. When first starting a fire, a medium- to high- firing rate must be maintained for at least twenty minutes. This ensures the stove, catalyst, and fuel are all stabilized at the proper operating temperatures.

Even though it is possible for the fire to get quite hot within a few minutes after a fire is started, the combus-

WinterWarm Small Insert

tor may stop working or the fire may go out if the fire is allowed to die down immediately as a result of the damper being closed. Once the combustor starts work- ing, heat generated by burning the smoke will keep it working.

To determine whether the combustor is operating, com- pare the amount of smoke leaving the chimney when the damper is open and when it is closed. This proce- dure is described on Page 17.

Starting and Maintaining a Wood Fire

Burn solid wood fuel only in the WinterWarm Small Insert, and burn it directly on the grate. Do not elevate the fuel. Do not burn coal or other fuels.

Cast iron is a superior material for solid fuel stoves but it must be treated with respect. It is extremely strong, but can be broken with a sharp blow from a hammer or from the thermal shock of rapid and extreme tem- perature changes. It is important to temper the cast iron plates with an initial series of 3-4 break-in fires. The plates expand and contract with changes in tempera- ture. Minimize thermal stress by allowing the plates to adjust gradually during the break-in fires by following Steps 1-3 on the following page.

Always be certain the damper is open when starting a fire or when re-fueling. To open the damper, lift up on the lever and move it to the right. (Fig.12)

Closed	Open
	Damper Control Lever
	FP1102
Fig. 12 Damper control.

WARNING: Operate your WinterWarm Small Insert only with the door fully closed. If the door is left partially open, gas and flame may be drawn out of the fireplace opening, creating risks of both fire and smoke.

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