Upon arrival customer stated that system was having a burnt smell when they turned the heat on. After inspection of 3 year old system found that insulation on the inside of door pulled into system and was blocking half of the blower wheel not allowing any airflow in the daycare area. I secured the insulation back to panel, checked system the 20kw heater is properly working. Systems only has electric heat. Blower wheel is clean, evaporator coils was starting to develop build up. Changed customer supplied filter was very clogged and dirty. Started system back up and system is heating with no issues. Spoke with owner of daycare she is interested in receiving a free estimate to replace two systems at her home office will reach out to schedule. System does not have any flood protection on it sent customer estimate to add with Uv light.