This thermostat is an automatic control of wood, pellets, coal or anthracite fired solid fuel appliances like room heaters, boilers, stoves, central heating units.
Its modulating action provides economy in fuel consumption.
Operation principle: It controls the combustion by throttling the primary air intake to the fire. A flat damper plate at the end of the control arm is moved relative to the air intake port of the appliance in response to variations of temperature at the bulb.
It is actuated by the expansion of liquid in the bulb, through capillary tubing to a diaphragm located in the body.
Body: Zinc plated steel
Shaft: Dia. 6mm, with 4.8mm flat, with 270° angular rotation.
Fixing: By means of the backside bracket, for dia 4mm screws, distance 42 to 48mm (Front mounting by 2 screws M4, 28mm distance available on request)
-Room Air Control 4/40°C (40/105°F). Damper displacement between 4 and 40°C (40/105°F), with a 170mm length arm: 12.5mm
-Hot water 30/90°C (85/195°F)). Damper displacement between 30 and 90°C (85/195°F), with a 170mm length arm: 9.5mm
-Flue temperature 50/300°C (120/570°F). Damper displacement between 50 and 300°C (120/570°F), with a 170mm length arm: 9.5mm
Other temperature ranges and displacement available on request (MOQ apply)
Damper plates are available in circular form in dia. 80mm and dia. 120mm. (Rectangular forms on request).They are spring mounted to permit self-alignment of the plate in the closed position.
Damper plate position can be adjusted from 150 to 170mm on the arm.
Damper plates are fitted with a temperature resistant silicone gasket. Special arm length and damper plates may be made on request to suit application (MOQ apply).
Bulb and capillary are made of stainless steel.
Bulb standard dia. 3, 6 or 8mm. (Depends of temperature ranges)
Standard capillary length 300 mm or 1500 mm
Main references with 170mm arm
|Damper disc diameter||Capillary length||
Temperature ranges (°C)
(bulb dia. 6mm)
(bulb dia. 8mm)
(bulb dia. 6mm)
(bulb dia 3 mm)
|80 mm||300 mm||WQD0440AC60080G0||WQD0440AC80080G0||WQD3090AC60080G0||WQD50C0AC30080G0|
|80 mm||1500 mm||WQD0440AO60080G0||WQD0440AO80080G0||WQD3090AO60080G0||WQD50C0AO30080G0|
|120 mm||300 mm||WQD0440AC600C0G0||WQD0440AC800C0G0||WQD3090AC600C0G0||WQD50C0AC300C0G0|
|120 mm||1500 mm||WQD0440AO600C0G0||WQD0440AO800C0G0||WQD3090AO600C0G0||WQD50C0AO300C0G0|
Many other printed knobs available, see our catalogue #1