Crandall TK-1001-600-CSS Thermostat

The Crandall Stats & Sensors TK-1001-600-CSS Aspirated Pneumatic Thermostat is a direct-acting, 2-pipe room thermostat in the aspirated -600 style of the TK-1001 series. Direct-acting means branch output pressure rises as room temperature rises. An aspirated thermostat uses a small flow of supply air through an aspirator to draw room air across the sensing element, so the thermostat reads actual room temperature instead of the wall temperature behind it. In the TK-1001-600 series the aspirated thermostat mounts in an AT-509 wall box behind a brushed stainless steel cover.

The factory photo shows the working mechanism: a copper-colored linkage on a dark cast base, a white dial wheel with its temperature numbers, the black main tube and white branch tube, and the flat brushed metal cover plate with its louvered slots that admit room air. Direct-acting pneumatic thermostats in this series run on 15 or 20 psig supply air, use 5/32-inch tubing with a black main and white branch, and have a throttling range adjustable from 2 to 10 degrees F per 10 psi. The Crandall installer's guide for the TK-1001 series puts the maximum safe ambient at 150 degrees F and air capacity at 16 scim for the standard two-pipe models. The TK-1000 series user guide lists 41.5 scim air consumption and 56 scim capacity for the TK-1001-600, against 13.8 scim and 16 scim for the standard TK-1001, so allow for the higher air use when you size the compressor and mains.

The -600 suffix is the aspirated version across the TK-1001 and TK-1101 series. The reverse-acting aspirated counterpart is the TK-1101-600, and the matching Crandall part is TK-1101-600-CSS, so check the action on your existing thermostat before you order. Mount the thermostat where room air can circulate to the louvered cover, keep it away from sunlight, lamps and heat sources, and keep the cover openings clear of paint, dust and wall coverings, because a blocked aspirator reads slow and inaccurately. After installation, check calibration with a test gauge on the branch line against an accurate thermometer, then verify the action by turning the dial through its range and watching the branch pressure respond.

Key Benefits

• Aspirated sensing: Draws room air across the element, so the thermostat reads actual room temperature and not the wall behind it.
• Direct-acting heating action: Branch pressure rises with room temperature, matching the TK-1001 series.
• Standard two-pipe pneumatic connections: 5/32-inch tubing, black main, white branch, on 15 or 20 psig supply air.
• Flush cover plate: A flat metal cover with louvered slots gives a clean wall appearance in finished spaces.

Common Questions

What does aspirated mean on a thermostat?
A small flow of supply air through an aspirator pulls room air across the sensing element, so the thermostat responds to true room temperature instead of wall temperature.

Is the TK-1001-600-CSS direct-acting or reverse-acting?
Direct-acting: branch pressure rises as the room warms. The reverse-acting aspirated version in the series is the TK-1101-600.

What supply air does it use?
Clean, dry, oil-free air at 15 or 20 psig, with 5/32-inch tubing: black for the main and white for the branch. Aspirated thermostats use more air than the standard two-pipe models.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.