When I arrived, I was told the smoke alarms went off during night. I let owners know that the fumes and oil from first running furnace are burning off. The smell was normal operation in beginning of furnace start up, I opened all windows up on both floors. Turned heating on, and let smell vent out of home for the next hour. Owners feel safe now, we’re just worried about smoke alarms going off. Went to check furnace out, no gas leaks. Installation was done correctly. Charging for diagnostic only toda.