Today I arrived on site Initial Assessment: Responded to an emergency call for a furnace unit not working, which is the primary heating system for the entire house. Problem Identification: Discovered the filter was heavily covered with dust. Maintenance Action: Noted the blower wheel also needs to be cleaned. Upon arriving at the property, The client explained to me that in the early morning the furnace unit stopped working. I proceeded to verify the furnace unit. I found a hard lockout on the circuit board indicating that the heater exchange was overheated. High Limit switch open. I proceeded to replace the air filter. Reset the unit. I started the system and monitoring for about 15 minutes. The system did not present faults or malfunction after concluding with the verifications. I explained to the client that he must be aware of replacing the air filter every three months at least. I also explained and recommended that you should schedule the appointment to do the blower wheel deep