Unit Heater (MIL-U-17293)

Inspect and clean evaporator and condenser coils for biofouling, scale, and corrosion — critical in high-salt marine environments

Check and replace air filters (HEPA/pre-filters) per schedule; verify filter housing seals and differential pressure across filter banks

Inspect fan blades, bearings, and drive belts/couplings for wear, vibration, and balance; lubricate bearing assemblies as required

Verify seawater strainer on condenser cooling water inlet is clean and free of blockage; inspect sea-water condenser for corrosion and tube integrity

Check refrigerant charge level and inspect for leaks at all connections, valves, and fittings (R-134a / R-407a systems)

Inspect and test shock mounts and vibration isolators for degradation — essential for navy shock-hardened installations

Verify operation of controls, thermostats, and remote controllers (MIL-C-2212 compliance where applicable); test safety interlocks and alarms

Inspect drain pans and condensate drain lines for blockage, corrosion, and proper slope; check insulation integrity on cold surfaces to prevent condensation and corrosion