Bi-metallic control device

A bi-metal closure valve for an air supply inlet for the combustion chamber of a wood stove, comprising:

• a casing mountable to the wood stove to enclose the closure valve;
• a free pivoted L-shaped flap, the flap having a first portion and a second portion extending from a pivot position and supported by the casing, the first portion positioned over the air supply inlet and retained over the inlet by gravity;
• a crank arm supported by the casing to rotate and push against the second portion of the flap to open the flap a predetermined amount;
• and
• a bi-metal strip coil having an outer end attached to the casing and a floating inner end attached to the crank arm, the strip coil being positioned to detect the temperature of the combustion chamber of the wood stove such that a change in combustion chamber temperature causes the crank to rotate to open the flap or allow the flap to close by gravity to vary combustion in the wood stove.