Start by confirming cooling mode and a temperature setting below the current room temperature. If the system remains unable to cool, describe the behavior before assuming which part is faulty.
Heat Pump Repair Pro provides repair in Littleton, with same-day and emergency service available.

Separate an airflow change from a temperature problem
Is there very little air at the registers, or is there normal airflow that does not feel cool? Check accessible filters and unobstructed registers according to your equipment instructions.
Look at the outdoor equipment from a safe position. Report whether it appears to operate and whether there is visible ice. Do not reach into the fan or remove electrical covers.
Compare the affected rooms
Tell us whether every room is uncomfortable or the issue is concentrated upstairs or in one area. Also note whether the system worked normally earlier that day or has struggled for a longer period.
Those distinctions help describe the problem. They do not establish whether it is an equipment fault, airflow issue, or another condition.

Avoid repeated resets
Repeatedly restarting a system does not resolve a continuing fault. If a breaker repeatedly trips, stop resetting it and arrange professional service. Internal electrical, refrigerant, and mechanical work requires appropriate training and tools.
What if my heat pump heats but does not cool?
Report the difference between the two modes. Mode-control and refrigerant-system operation may need investigation; a symptom alone is not proof that a reversing valve must be replaced.
Request cooling-mode repair
Call (720) 571-0599 and tell us what changes when cooling is selected. For estimate questions, see our repair cost guide.