Found thermostat set to off and gas shut off to furnace. (Customer shut gas off earlier, because system wasn’t working). Turned it on and gas valve on furnace, did not open 2 times in a row when voltage was going to it. Made sure all connections were tight and cycled power. Gas valve did open, but furnace tripped on flame safety. Flame safety is failed. Installed a new one. Cycled power several times and furnace worked every time. If furnace has issues again, may need to look into a new gas valve. Due to age and condition of equipment, replacement is encouraged. Chris will come out tonight to quote a furnace.