Gas Heater won’t ignite

Gas Pentair Mastertemp Help

At opening would not ignite. Continually cycled to ignite until timing out and Service Heater light comes on at end. Blower sounds and felt fine along with strong exhaust.

Board showed anAFS fault. Upon removing cover to replace AFS the fault cleared. Replaced AFS anyway.

Still no ignition. Service Heater light still comes on at timeout, but no fault LEDs light.

Inspected igniter and tested. Works fine. Tested voltage to gas valve terminals 24v and 24v on the other side when you hear the “buz” as it cycles. There is absolutely zero smell of gas.

Is there a way to test/manually open the gas valve to ensure a: there is gas reaching the valve and b: it’s truly the valve that is bad?