Carrier KH03HL005 Air Filter 326070-701 or the control board throwing

or the control board throwing a specific flash code indicating a pressure switch circuit stuck open or closed

this low voltage relay ensures the control circuit maintains stable communication between the thermostat and the high-voltage blower motor

port erosion

Key Benefits Eliminates Nuisance Trips: Bypasses the low-pressure switch for 180 seconds to allow for pressure equalization in cold environments

a separate coil must be sourced

Carrier KH03HL005 Air Filter 326070-701 or the control board throwingThe Carrier KH03HL005 is a high performance 20x25x2 air filter engineered specifically for commercial and industrial HVAC applications. This Factory Authorized Part features a robust aluminum mesh construction, offering a permanent, washable alternative to standard disposable media. With a nominal depth of 2 inches (actual depth 1 3 4 inches), it fits precision Carrier filter tracks without requiring frame modifications. Unlike standard 1 inch