Customer complaint
What the customer noticed
A rental RV owner called about a guest at All American Campground in Bristol whose front bedroom air conditioner was not working. The lower air box was also loose and unusually loud.
Diagnostic findings
What inspection and testing revealed
Removing the lower air box revealed an evaporator coil frozen solid and a freeze sensor that had not been inserted into the coil. The ducts were unobstructed. The plenum divider had been installed diagonally instead of separating the return and supply air, allowing the two air streams to mix. Several missing air-box screws also left a loose ceiling seal that allowed air to escape. After the ice melted, the evaporator coil was found to be dirty.
Work performed or recommended
What Sunset did or recommended
Allowed the frozen coil to thaw, cleaned the evaporator coil, and inserted the freeze sensor into the coil. Reinstalled the plenum divider in the proper position and reinforced and sealed it with HVAC foil tape. Replaced the missing lower air-box screws and secured the assembly against the ceiling.
Outcome and next step
Where the service call stands
The Coleman Mach 15 was operating properly after the repairs, with satisfactory amp draw. Final temperature readings were 77.9°F at the return and 60.6°F at the supply, a 17.3°F temperature split.