Modine 5H0794410009 Pressure Switch

The Modine 5H0794410009 Pressure Switch is the official OEM replacement part for legacy part number 5H79441-9. Specifically calibrated to a 0.80" WC set point, this SPST (Single Pole Single Throw) air pressure switch is a critical safety interlock for Modine unit heaters, including the HD100, HD125, and PTS200 series. Its primary function is to verify that the inducer motor is creating sufficient negative pressure to safely vent combustion gases before allowing the ignition sequence to proceed.

Built for the rigors of industrial and commercial heating, this vent pressure switch ensures high-accuracy monitoring of the flue vacuum. If the switch detects a blocked vent, failed draft inducer, or cracked pressure tubing, it will automatically break the circuit to prevent short cycling or dangerous exhaust buildup. For field technicians, this factory-authorized component provides a drop-in fit with 1/4" connectors, eliminating the need for universal pressure switch kits that require complex field adjustment.

Key Benefits:

• Precise 0.80" Water Column Rating: Ensures the system operates within exact manufacturer specifications for combustion safety.
• Direct OEM Replacement: Seamlessly replaces 5H79441-9 with the correct mounting footprint and electrical terminals.
• High-Cycle Reliability: Engineered to withstand the frequent startup cycles of gas-fired unit heaters.
• System Protection: Critical for preventing ignition in the event of heat exchanger failure or flue obstructions.

Common Questions:

What are the symptoms of a failing pressure switch in a Modine heater?
Common indicators include the inducer motor running continuously without ignition, the control board flashing a pressure switch stuck open error code, or the burners shutting down immediately after a brief flame light-off.

Can I use a higher WC rated switch as a substitute?
No. Using a switch with an incorrect pressure rating can lead to unsafe operation or frequent system lockouts. Always match the 0.80" WC requirement specified for your Modine HVAC equipment.

Does this switch come with replacement tubing?
This is the switch assembly itself. If you are experiencing failure, it is recommended to also inspect your silicone pressure tubing for cracks or moisture buildup that could impede the vacuum signal.

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.