Troubleshooting Frozen Evaporator Coils On A New Advent Air Rooftop AC Unit

Updated 07/29/2021 | Published 07/27/2021

Question:

I recently replaced my domectic AC units with an advent air unit. I left the thermostat on AC Auto set at 70 and we were gone most of the day. When we returned home that evening the units were running but the motorhome was hot. I checked the AC and it was frozen. This is the second time it has happened.

asked by: Dan C

Helpful Expert Reply:

Normally if an Advent AC unit like the # ACDOM150 freezes over it means the filter is dirty or the air louvers are being blocked. Remove the power and let the evaporator coils thaw and then check the filter and make sure the louvers are properly positioned so that cold air isn't being blown back up into the unit and causing the freeze up. Since it's a new unit it could be a factory defect and wasn't properly filled with refrigerant. There are ports on these units that allow condensation to drip out onto the roof of the RV so you'll want to ensure there isn't anything blocking or plugging them up.

If this does not solve your freezing issue please reply back and we'll keep troubleshooting.

expert reply by: Kevin C