EcoService OS

Rooftop Unit Not Cooling

  • Interactive decision labs
  • Built by working technicians
  • Path-based verifiable certificate
  • Exam preparation only
  • Worldwide online
Commercial HVAC / RTU
~15 min
intermediate

The call

Retail space is warm. Thermostat is calling for cooling, the supply fan runs, but the air out of the diffusers is not cold.

Equipment
5-ton packaged rooftop unit, R-410A, single-stage cooling, gas heat section, economizer fitted
Ambient
96°F
Site notes
Unit is on a flat roof with a parapet close to the condenser. Filters were changed last month.

Decision 1 of 5

You are on the roof with the panels still on. The supply fan is running.

What is your first move?

Where this lab sits

This is one module lab from Commercial HVAC / RTU. The full path adds sealed systems, defrost, rack-system orientation and natural-refrigerant safety, each ending in a lab like this one.