Tjernlund Products DC4 Draft Control 326010-701 It should not be used

It should not be used to bypass safety circuits or modify the original design of the HVAC system

and solar applications where lead-free compliance is mandatory

Verify 24V power at the switch terminals and check the induction tubing for clogs or cracks

Professional installation is recommended to ensure seamless compatibility with the existing boiler control system and to maintain the safety standards of your gas-fired equipment

the latter is simply the updated SKU used in current Trane parts catalogues

Tjernlund Products DC4 Draft Control 326010-701 It should not be usedThe Tjernlund DC4 Draft Control is an essential component for technicians managing combustion efficiency in residential and commercial heating systems. This 4 inch single acting draft control is precision engineered to maintain a consistent neutral draft within chimneys and vents, effectively counteracting fluctuations caused by changing barometric pressure, stack temperatures, and wind velocity. Fabricated from heavy duty corrosion resistant steel,