A replaceable heating cartridge for use with a warming device to heat or warm a fluid. The replaceable heating cartridge comprises a heater having first and second sides, a first connecting portion to receive a fluid from an external source, a second connecting portion to supply a heated fluid, a plurality of barrier members disposed on each side of the heater, and a pair of cover members. Each cover member is disposed on one side of the heater and configured to couple to each other with the heater and the barrier members therein between to form a body with a fluid path. The fluid path wraps around the heater multiple times to warm the fluid flowing through the fluid path from the first connecting portion to supply the heated fluid at the second connecting portion. An air filter is disposed on the fluid path to remove air from the fluid. Preferably, one of the cover member further comprises a plurality of openings to discharge the air removed from the fluid by the air filter.