Tom M. 1-20-25. No heat. Customer stated sometimes the system doesn’t run but then 30 minutes later it will. She believes it could be dirty. System was installed by another company a year ago. I showed the customer inside the furnace and it’s not dirty there is a slight coating of dust on the blower wheel. The ducts are dirty and need to be cleaned. She stated she doesn’t want to go through that expense. The furnace has an intermittent issue with the circuit board. It flashes a code then goes blank and repeats even with the door switch not closed. The circuit board is extremely difficult to get to. She’s goin to call the company that installed the furnace. I have quoted for the repair in case she needs us to do it